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Residential Light Commerical Rev 1.1

1. 0 eee eeeeeeeeeeeeeeeeeeeeteeeeeeeees 11 Task 11 System COMME COMMS cicecc cee ccc cevnced coxnndeecercndeccevcndencerncdtemumcmdanmennmceemenncderters 11 Task 12 System Evacuation Efficiency Startup and Charging ceceeeee 12 Category D Comfort Cooling Warecacvacsnsraccaeiasnvaecdeliruniiscdiiaenisciatie 13 Task 13 Ind or alr Quality sss rsin naiiai aa gaoa raea aapea eee 13 Fask 14 Alr filtration aiaia niaaa aa ee a Ai dik aAa AaS 13 Task 15 AuUmIicity and FMIGiCatONitsc inciaciactaliine tonic iscit eincincadtaisciinton 13 Page 5 of 120 Rev 1 1 4 22 07 Task 16 Installing and troubleshooting air quality deVICES eeeeeeeeeeeeeeeeeteees 14 Category E Comfort Cooling Troubleshooting ceeeeeeeeceeeeeeeeeeeeeeeenneeeeeeeeeeeeeees 14 Task 17 Evaporator and condenser fan motor problemsS 2 cceeeeeeeeeeeeeeeteees 14 Task 18 Refrigerant charge related problems ccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaaees 14 Task 19 Evaluating the metering A VICC cceeeeecesccceeeeeeeeeeeeeaeeeeeeeeeeeeeeeeeaaeees 14 Task 20 Troubleshooting steps 8 ole ee ea a ee ae ake 15 Category F Refrigerant Management ssssssssssssssesssssesssessseesseseseeseeeeeeeees 15 Task 21 Refrigerant and oil t V pS acc n2es aves eia ens aieeealis 15 Task 22 Refrigerant handling and transporting regulations ccceeeeeeeeeeeeees 15 Ca
2. UA STAR Residential Light Commercial HVACR Service Technician Study Guide With Practice Exams United Association Training Department amp FERRIS STATE UNIVERSITY The University Center for Extended Learning Corporate amp Professional Development Services FORWARD This Study Guide is designed to assist you in locating information in UA Textbooks and other sources that relate to the 11 categories and 46 tasks identified during the DACUM Develop A CUrriculuM process administered by Ferris State University The DACUM is an in depth job and task analysis that serves as the base for the UA STAR exam The 11 categories and 46 tasks identified during the DACUM are included in this Study Guide so that you can see first hand the results of the study and the items that you can expect to encounter on the UA STAR exam Each category and task is numbered and each task is broken into a number of smaller jobs that a technician would be expected to perform in order to complete the task Below each task you will find an underlined paragraph that looks like this and contains general reference to UA textbooks and other sources In some cases specific pages are cited In others chapters but in most only general reference is given You will find that the UA STAR exam is a comprehensive exam It is designed to test the knowledge of the experienced technician As such this Study Guide is intended to be a reference for the experience
3. a Occupational Safety amp Health Administration b American National Standards Institute www ansi org c Air Conditioning Contractors of America d None of the above ANSI is the organization for U S and world wide industry standardization C Installation UA HVACR Training Manual UAHTM unit 37 C 10 Unit Location and Air Distribution System C 10 c 40 Identify the air distribution system used in modern residential buildings in which the air pressure remains steady from one end of the system to the other a Radial duct system b Reducing plenum system 37 12 c Perimeter loop system d Flex duct Radial systems are seldom used today for supply air delivery because of a difference in pressure and volume of the air delivered through each opening The reducing plenum system delivers a more uniform pressure and volume to each outlet Flex duct is a distracter and does not apply to this question C 10 c 41 When installing galvanized rectangle duct 8 x 20 the metal should be at least a 16 gage b 24 gage c 28 gage f 37 28 d 32 gage Page 73 of 120 Rev 1 1 4 22 07 16 and 24 gauge may be used on larger dimension duct work and 32 gauge may be used for smaller dimension duct work but 28 gauge is the standard for 8 x 20 ductwork C 10 b 42 When the proper size duct materials are used the occupants of the home should a Not feel air movement b Should not hear air noise c Should not feel temperature swing d All of the
4. A 3 e 21 lf a motor operating 1725 RPM is turning a blower wheel at 500 RPM and the blower pulley is 12 what is the diameter of the motor pulley a 2 5 inches b 3 inches c 3 5 3 5 inches3 5 1725 x 12 use formula page 437 d 4 inches 500 See formula A 3 g 22 How many watts are required to operate a 1 hp motor for a period of 1 hour a 74 6 watts b 746 watts UAHTM 2 14 c 7460 watts d None of the above A 1 horsepower motor operating for 1 hour will require 746 watts of power B Safety UA HVACR Training Manual UAHTM B 4 Personal Safety B 4 a 23 A technician must use every precaution when working with pressure electrical energy heat cold rotating machinery chemicals and when lifting heavy object a To protect him her self b To protect others in the area c To act as a professional d Allofthe above UAHTM Summary Each area of safety is of equal importance and the technician must also be aware of others in the vicinity B 4 d 24 One of the most overlooked safety devices in this industry is a Safety glasses UAHTM 4 intro p 67 b Steel toed shoes c Leather gloves d Self contained breathing apparatus Eye injury is one of the most often reported injuries and is most easily prevented Page 68 of 120 Rev 1 1 4 22 07 B 4 c 25 Wearing metal jewelry can be most harmful because of a Frost bite b Shock or electrical burn 4 2 c Magnetic electrical energy d Electrical ground fault Although fros
5. Electric shock Ground wires Extension cords and ground prongs Ground fault circuit interrupters Reference United Association HVACR Training Manual Unit 4 Page 9 of 120 Rev 1 1 4 22 07 Task 6 Fire safety Class A B C and D fire extinguishers Multiple purpose fire extinguishers Fire extinguisher use Fire extinguisher maintenance Reference www hanford gov fire extinrs htm fetypes Task 7 Tools equipment and material safety Wrenches Screwdrivers Ladders Soldering and brazing equipment Pressurized gas tanks and cylinders Chemical and material safety Reference United Association HVACR Training Manual Unit 4 Task 8 First aid Frostbite Bleeding Asphyxiation Chemical burns Electric shock Reference United Association HVACR Training Manual Unit 4 www chp edu besafe adult 02frostbite ohp base hs Task 9 Agencies Occupational Safety and Health Administration OSHA National Fire Protection Agency NFPA American National Standards Institute ANSI Reference http www osha gov http www ansi org Page 10 of 120 Rev 1 1 4 22 07 Category C Installation Task 10 Unit location and the air distribution system Condensing unit location sound transmission wind factors location of electrical power airflow restrictions proximity to the indoor unit ground slope Indoor unit location types of air distribution systems location of electrical powe
6. Fiberglass C Pleated D HEPA 62 The recommended humidity level in homes or buildings is A no more than 20 B 20 40 C 40 60 D at least 70 63 Duct mounted bypass humidifiers allows air from the supply duct to A flow directly to the return air duct B pass through a media C be heated before entering the humidifier D all of the above 64 Humidifiers should only operate A when the air handler blower is operating B when the humidistat signals for an increase of humidity C when the system control is set for cooling D both a and b 65 What is the maximum hardness of the water allowable for atomizing type humidifiers A 1 3 grains B 8 10 grains C 20 30 grains D up to 50 grains 66 High quality energy recovery ventilators A use high volume blowers to exhaust stale air B use a heat exchanger to absorb heat from the air being exhausted C use a small heater to make up heat lost due to incoming fresh air D all of the above Page 38 of 120 Rev 1 1 4 22 07 67 To help prevent allergic reactions or upper respiratory problems humidifiers should be A cleaned regularly B treated with algaecides C drained regularly D all of the above 68 To kill mold and algae and to prevent them from contaminating the area some manufacturers use A UV lights B radon C fungicides D all of the above 69 The required condenser air flow is approximately A 400 CFM per ton B 600 CFM per ton C 800 CFM per to
7. Once you have taken the practice questions you can check your answers using a separate document from the UA This document contains explanations for most of the correct and incorrect answers Task links are also provided with each question These links direct you to specific areas of the DACUM From there you can locate the UA text to use for reference on your specific area of interest 1 Matter is commonly explained as a substance that occupies space and has A mass B solid C liquid D gas Solid mass exerts pressure A in all directions B downward only C down and outward D all of the above Liquid mass exerts pressure A downward only B in all directions C down and outward D all of the above The Law of Conservation of Energy states that energy is neither created nor destroyed but A is renewable B can be converted from one form to another C is not renewable D both a and b Page 29 of 120 Rev 1 1 4 22 07 5 Dalton s Law of Partial Pressures shows that the total pressure of a confined mixture of gases is A an average of all the gases combined B the least pressure of each of the gases C the sum of all the gases D not measurable 6 Heat flow is always in the direction of A hot to cold B cold to hot C lower to higher D higher to lower 7 Latent heat is experienced A when the earths temperature decreases B water turns to steam C when ice melts D both b amp c C F
8. Page 113 of 120 Rev 1 1 4 22 07 K Light Commercial UA HVACR Training Manual UAHTM HVAC Light Commercial STC Version 1 11 06 Modern Refrigeration and Air Conditioning Air Conditioning Mechanical Equipment Service Manual for UAJA Practical Heating Technology Johnson Delmar Electricity for Heating Refrigeration and Air Conditioning ARI Refrigeration and Air Conditioning 4 Edition http www osha qgov pls oshaweb owadisp show _document p table STAN DARDS amp p_ id 10405 www osha gov Publications 3100 html K 42 Roof Top Packaged Units K 42 a 185 Parallel compressors are piped into a system in such a manner that a The discharge lines are connected to a common manifold b The suction lines are connected to a common manifold c The liquid lines are connected to a common manifold d Botha and b UAHTM 26 6 Dual compressors could be piped in 2 different configurations parallel and series In a parallel system all discharge lines are common to each other as well as all suction lines are common to each other K 42 a 186 An advantage of the parallel compressor systems would be a Load matching b Higher efficiency c Less compressor cycling d All of the above UAHTM 26 6 There is a long list of advantages of a parallel compressor set up when capacity requirements change compressors can be brought online to match the demand overall system efficiency is improved and less compressor cycling will occur Page 114 of 120 Re
9. Reference Air Conditioning Mechanical Equipment Service Manual for UAJA Task 46 Rooftop safety and hazards Exhaust ducts on roof Ladders Rigging and Openings and skylights Roof access Remove equipment and materials used on roof Gas piping Reference Air Conditioning Mechanical Equipment Service Manual for UAJA Practical Heating Technology Johnson Delmar www osha gov Page 25 of 120 Rev 1 1 4 22 07 Formulas Energy Calculations QiTotan 4 5x CFM x Ah Qisensibiey 1 10 x CFM x AT Q BTUH Ah difference in enthalpy Ag difference in grains of moisture AT difference in temperature Heat transfer BTUH LB x AT x Specific heat for any substance BTUH CFM x AT x1 08 for standard air BTUH GPM x AT x 500 for water Force exerted by a round diaphragm with a pressure applied and measured in psig Force Area x Pressure _ pound sq in x sq in mr x psig Pressure conversions 1 psi 2 31 feet of head 1 psi 27 7 in w c 1 psi 2 04 in Hg 1 atmosphere 34 feet of head 1 atmosphere 29 9 in Hg 1 atmosphere 14 7 psi w c water column in Hg inches Mecury Air pressure in ducts V 40054 VP 2 vpr Airflow in duct Q AxV Q CFM A Cross sectional area of duct ft V Velocity of air feet per minute FPM VP inches water gage WG Mixed air temperature MAT MAT OAT x WOA RAT x RA Percent of outside air RAT MAT RAT OAT MAT
10. When gas pipe is installed across a roof the pipe must be a Fastened with galvanized joints b Sealed with Teflon tape c Supported and fastened PHT 4 1 d All of the above Gas pipe must be installed in accordance with state and local codes Joints should be made with malleable black pipe and fittings and sealed a soft set thread compound Gas pipe must also be supported to prevent sagging and fastened to keep the system secure According to OSHA falls from are one of the leading causes of occupational fatalities and injuries a Ladders www osha gov b Roof tops c Windows d Cranes OSHA statistics show falls from ladders are one of the leading causes of occupational fatalities and injuries OSHA recommends when climbing a ladder a Keep your body out away from the ladder as far as possible b Keep your feet as far to the outside of the rungs as possible c Maintain a 3 point contact with the ladder at all times www osha gov d All of the above The recommendation by OSHA is 3 point contact with the ladder at all times This means 2 hands and 1 foot or 2 feet and one hand should be firmly set on the ladder when traversing up or down the ladder Page 119 of 120 Rev 1 1 4 22 07 K 46 e 205 Design specifications for Suspended Personnel Platforms require the support platform rating be at least the maximum intended load a 2times b 3 times c 5 times d 7 times According to OSHA suspended personnel
11. charge is not practical and the pressure temperature chart must be applied followed by superheat measurement E 18 a 75 Starting up an air conditioning system with the indoor temperature at 85 degrees f and the Rh at 70 would be considered a An excessive load UAHTM 41 5 b A normal load c A light load d None of the above This is an excessive load at 85 degrees it is a high sensible load and with 70 Rh this is considered a high latent load Sensible plus latent equals the total heat load A normal load would resemble a 75 degree indoor temperature with a 55 60 Rh E 18 b 76 During a complete loss of charge condition with a leak on the systems low side and the systems low pressure cut out control has opened the technician must consider a Finding and repairing the leak b Contaminant in the system c The compressor will not start until the system is recharged d All of the above UAHTMf 39 22 First it is essential the refrigerant leak is located and repaired Second typically the low pressure safety cut out is set at just above atmospheric pressure 2 5 psi If the low pressure switch opened then Page 82 of 120 Rev 1 1 4 22 07 it is also likely that the system pressure dropped to 0 psi or lower and contamination has occurred and an evacuation must be performed Finally the technician must realize the compressor will not restart until the system pressure is restored E 18 c 77 After a system evacuation can cause a micron gauge t
12. gases Energy First and Second law of Thermodynamics Work Power Heat heat and power relationship temperature and temperature scales heat transfer sensible heat latent heat Pressure atmospheric pressure vacuum pressure vacuum pressure calculations and conversions Reference United Association HVACR Training Manual Unit 1 and 2 Task 2 The Refrigeration Process The refrigeration process pressure temperature relationship evaporators compressors condensers metering devices Refrigerants in the residential systems R 22 R410A The vapor compression refrigeration cycle putting it together outside air conditioners from the compressor in the condenser through the metering devices indoor air conditions absorbing heat in the evaporator in the compressor Reference United Association HVACR Training Manual Unit 3 P T Chart Page 8 of 120 Rev 1 1 4 22 07 Task 3 Applied HVAC math Basic algebra CFM Measuring linear cubic square volume GPM flow rates Pulley formula Micron Conversions Reference United Association HVACR Training Manual UA Star Equation sheet Related Mathematics Category B Safety Task 4 Personal safety Clothing Jewelry Safety glasses Work boots Ear plugs Gloves Lifting objects and back support belts Reference United Association HVACR Training Manual Task 5 Electrical safety
13. 32 A leaking refrigeration system not only can cause severe frost bite but can also cause A asphyxiation B lightheadedness C heart arrhythmia D all of the above Page 33 of 120 Rev 1 1 4 22 07 33 When soldering or brazing near combustible materials a technician should always use a A flame retardant heat shield B bucket of water to soak combustibles C propane torch D all of the above E 34 If the working length of a ladder is 12 feet how far should the base of the ladder be placed from the adjacent wall A 2 feet B 3 feet C 4 feet D 6 feet 35 If a technician finds a person suffering from asphyxiation caused by breathing refrigerant he she should A call for help B immediately move the person to an area of fresh air C conduct CPR D find and fix the refrigerant leak 36 If you find a person who is suffering from an electrical shock and has no pulse you should A call for help B begin CPR immediately C drag the person to safety D turn off the building s power supply 37 When treating frost bite you should A gently rub the affected area B run warm water over the affected area C quickly warm the affected area with a heater or blow drier D quickly put on butyl line gloves 38 Which agency concerns itself with the health and safety of America s work force A Air Conditioning Refrigeration Institute B American National Standards Institute C Occupational Safety amp Health Administration D all of
14. 41 b 182 If a technician determines he can not keep a scheduled customer appointment he should a Travel as fast as possible to get there as soon as possible b Call the customer to keep them informed of your delay c Do nothing the customer expects service people to be late d Call the customer and tell them you have been on a more important service call Most customers recognize service companies technicians are very busy people and that scheduled appointments sometimes get delayed However the customer is likely just as busy and may even have to take time off from work to meet you Whenever you discover that you can not meet for a scheduled customer appointment at least be courteous and professional and give the customer a phone call so they are not left hanging They may not be happy that you have cancelled or postponed but it is far better than not making contact at all J 41 f 183 Background checks are necessary to disclose employee history associated with a Criminal records b Credit reports c Drug testing d All of the above Background checks can identify all of the above character faults In today s world background checks are a part of life we all must get used to J 41 d 184 Which of the following would be a display of professionalism a Work uniform with company logo b Being punctual c Use of good people skills d All of the above Professionalism is boundless all of the above are indicative of professionals
15. American Wire Gauge AWG the largest diameter wire is a 0000 4 0 EHRAC 8 1 b 2 gauge c Service lead wire d 50 gauge AWG identifies the lower number as a larger diameter 4 0 and the higher numbers are a smaller diameter G 26 Electrical service HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditioning G 26 b 120 Upon start up of a roof top air conditioning system it is found that the condenser fan motors are rotating in the wrong direction What should be done to correct the problem a Replace the motor with the correct rotation motors b Disconnect the power and change any two phase leads of the incoming power c Reverse the directional decal on the fan blades HVAC LC d Turn the fan blades over The problem in this scenario is that the phases legs of the unit do not match the phases of the power supply The correct response is to switch 2 of the legs of power at the condenser fan motor power supply G 26 a 121 A single phase 120 240 volt electric service is made up of a L1 L2 and Neutral HVAC LC b L1 and Neutral c L1 L2 and L3 d L1 L2 L3 and a ground An L1 and an L2 along with a neutral makes up a 120 240 volt single phase power supply 120 volts is derived from this service by using either L 1 or 2 phase and the neutral Page 95 of 120 Rev 1 1 4 22 07 G 26 b 122 refers to the number of currents alternating at different time intervals in the ci
16. Asphyxiation b Lightheadedness c Heart arrhythmia d All of the above f 4 17 All of the above are possible refrigerant vapors are heavier than air which displaces oxygen to a higher stratified level B 7 d 33 When soldering or brazing near combustible materials a technician should always use a a Flame retardant heat shield f 4 19 b Bucket of water to soak combustibles c Propane torch d All of the above Soaking of nearby combustibles with water is impractical and a propane torch is ineffective for brazing A heat shield should be used to protect equipment components as well as to prevent combustion of near by flammable articles B 7 c 34 If the working length of a ladder is 12 feet how far should the base of the ladder be placed from the adjacent wall a 2 feet b 3 feet f 4 17 c 4 feet d 6 feet The proper angle of a ladder placed against a wall is 1 foot away from the wall for every 4 foot of vertical rise Page 71 of 120 Rev 1 1 4 22 07 B 8 First aid and CPR UA HVACR Training Manual UAHTM unit 4 www chp edu besafe adults 02frostbite ohp base hs B 8 c 35 If a technician finds a person suffering from asphyxiation caused by breathing refrigerant he she should a Call for help b Immediately move the person to an area of fresh air UAHTM 4 7 c Conduct CPR d Find and fix the refrigerant leak The most important response would be to remove the person to safety first before beginning CPR or calling for hel
17. Heating Refrigeration and Air Conditioning Category Heating Task 30 Install and service electric heat Theory of electric heat The electric furnace Electronic furnace wiring interlocks thermostats multiple stage electric heating electric heating safety devices fan operation Installation of electric furnaces Electric duct heaters Installing duct heaters Troubleshooting electric heating systems airflow problems electrical problems Service call 1 defective sequencer Service call 2 defective blower motor Service call 3 blocked air filter Reference United Association HVACR Training Manual Electricity for Heating Refrigeration and Air Conditioning Task 31 Install and service gas furnace Combustion combustion efficiency complete combustion incomplete combustion Testing combustion the draft gauge the smoke tester Page 19 of 120 Rev 1 1 4 22 07 carbon dioxide tester stack thermometer Fuels natural gas manufactured gas liquefied petroleum The gas furnace Furnace components heat exchangers fuel delivery to the furnace the gas manifold primary and secondary air fuel ignition venting and removing products of combustion fan motor and blower fan switches limit switches Gas furnace installation install the gas piping install the vent piping on conventional furnaces install the vent piping on condensing furnaces Troublesh
18. The start winding ERHAC 10 3 The potential relay uses a normally close contact which opens when back or counter electromotive force EFM is built up as the motor starts rotating Much like an electrical generator produces EMF or voltage the start winding also produces a considerable voltage 144 After a defrost timer control initiates a defrost period the defrost cycle may H 28 j terminate by means of a Time pressure or temperature ERHAC 6 2 b Temperature only c Pressure d Time only Some defrost systems will terminate operation by time only others will terminate by pressure or temperature if the timer does not time out first 145 A solid state starting relay is employed with fractional horse power compressors after the motor starts the relay a Increases in resistance disconnecting the run winding b Increases in resistance disconnecting the start winding ERHAC 10 5 c Decreases resistance disconnecting the run winding d Decreases resistance disconnecting the start winding The solid state relay also called a positive temperature co efficient relay PTC relay very quickly increases in resistance which effectively eliminates current flow to the start winding Page 101 of 120 Rev 1 1 4 22 07 H 29 Elctrical troubleshooting H 29 b 146 When troubleshooting a capacitor start capacitor run motor and the technician finds the start capacitor and the run capacitor defective the technician must al
19. above 37 3 These conditions of comfort can all be achieved by a correctly designed and installed duct system C 10 c 43 When conditioned air travels through an unconditioned space such as an attic or crawl space the duct must be insulated if the air temperature difference is a 5 degrees f b 10 degrees f c 15 degrees f 37 23 d 20 degrees f A 5 or 10 degree difference in temperature is not of major significance but at 15 degrees or more the dew point is likely to be met causing condensation on or in the ductwork As well the greater the temperature difference the greater the amount of duct heat gain or loss causing higher energy cost C 11 System Connections UA HVACR Training Manual UAHTM unit 7 C 11 a 44 Air Conditioning Refrigeration ACR tubing is measured by its a Inside dimension b Outside dimension f 7 1 c Nominal dimension d Wall thickness Copper tubing used for air conditioning or refrigeration is identified by its outside dimension Waste and water tubing is measured by is inside or nominal dimension Wall thickness is typically identified as type K L or M C 11 b 45 On air conditioning systems the tubing is often insulated to reduce heat transfer to the refrigerant a Liquid line b High pressure line c Discharge line d Low pressure line 7 3 Page 74 of 120 Rev 1 1 4 22 07 The low pressure or suction line tube is insulated to reduce condensation on the tubing and to reduce unwanted heat gain of th
20. correctly B zone operation without water hammering C heating and cooling temperature control from the same thermostat D all of the above A geothermal heat pump absorbs heat A in the evaporator in the heating mode B in the condenser in the heating mode C in the condenser during the cooling mode D none of the above On a split system air source heat pump operating with an outdoor ambient of 30 degrees f the refrigerant boiling temperature would be approximately A 10 degrees B 10 degrees C 30 degrees D 70 degrees A coaxial heat exchanger used on geothermal heat pumps allows A water to flow in one direction and refrigerant in the opposite direction B water and refrigerant to flow in the same direction C water to flow only if the water check valve is open D none of the above Page 56 of 120 Rev 1 1 4 22 07 173 174 175 176 177 178 179 During the heating mode air source heat pumps must periodically defrost the outdoor coil some systems use time and or temp to initiate the defrost cycle Other modern systems use A alow pressure control connected to the indoor coil B ahigh pressure control connected to the outdoor coil C an air pressure switch sensing air pressure at the indoor coil D an air pressure switch sensing air pressure at the outdoor coil When attaching a document using Microsoft Outlook e mail you must A click on the forward icon B click on the papercl
21. defrost time and temperature initiation temperature termination defrost solid state defrost Geothermal heat pump theory geothermal heat pump system configuration Troubleshooting geothermal systems water circuit problems airflow problems Service call 1 Defective water pump Service call 2 Mineral deposits in the water circuit Reference United Association HVACR Training Manual Electricity for Heating Refrigeration and Air Conditioning Page 22 of 120 Rev 1 1 4 22 07 Category J Soft Skills Task 38 Computer skills Basic literacy Program thermostats Upload and download files move copy search Search internet and access web Adobe Connect to printer Reference United Association HVACR Training Manual Task 39 Documentation invoicing Fax Email Complete work orders Technically describe problems and situations Office procedures Invoicing accuracy estimate time Inventory control accurate records Reference United Association HVACR Training Manual Task 40 Customer relations Greet customers Vehicle appearance Communication skills Listening to customer skills Personal appearance Handling irate customers Handle complaints Explain operating instructions to customers Reference United Association HVACR Training Manual Page 23 of 120 Rev 1 1 4 22 07 Task 41 Ethics and professionalism Maintain valid driving license Time management scheduling book Vehi
22. heat from the refrigerant d Cause the refrigerant to condense into liquid form Making the product is a misuse of terminology a product is not made cold rather the heat is removed from the product Correctly stated the evaporator absorbs heat from the product c and d refer to the function of the condenser A 2 a 12 Residential and light commercial HVAC systems typically use a Reciprocating compressors b Rotary compressors c Scroll compressors d Any of the above UAHTM 3 8 Most typically rotary or reciprocating compressors are used in refrigeration systems while reciprocating and scroll compressors are Page 65 of 120 Rev 1 1 4 22 07 used in air conditioning systems Compressors not used in residential and light commercial HVAC systems would include centrifugal and screw type compressors A 2 d 13 The condenser receives hot refrigerant vapor from the compressor and a Cools the refrigerant causing a latent heat exchange b Adds heat to the refrigerant causing it to condense c Removes heat from the refrigerant causing a sensible heat change d Bothaandc UAHTM 3 9 The condenser receives heat laden vaporous refrigerant from the compressor then by cooling the vapor removing the latent heat the refrigerant liquefies b is incorrect heat is added to the refrigerant in the evaporator A 2 a 14 Residential and light commercial HVAC systems typically use a Capillary metering b Thermal expansion val
23. increase E 17 b 71 A condenser fan motor with sleeve bearings should be lubricated a 2times per year EHRAC 10 6 b 3 times per year c 4 times per year d Once per month The recommended lubrication interval is 6 months or twice per year More often is not necessary E 17 c 72 Improper blower pulley alignment can cause a Unnecessary wear b Erratic speed c Premature belt failure d All ofthe above EHRAC 10 7 When motor and blower pulleys are not properly aligned all of the above symptoms are possible Page 81 of 120 Rev 1 1 4 22 07 E 17 d 73 V Belt tension should be set to about a Yeinch b 1 inch EHRAC 10 7 c 1 Yinches d 2 inches Proper belt tension is about 1 If set tighter additional wear may be noticed as well as increased noise If set too loose the belt will likely slip reducing overall air flow and system capacity E 18 Refrigerant Charge and Related Problems UA HVACR Training Manual UAHTM unit 41 E 18 a 74 To add refrigerant to a partially charged air conditioning system a technician should read the manifold gauges and then a Compare to a Pressure Temperature Chart UAHTM 41 5 b Consult with the manufacturer c Recover the existing charge and weigh in the correct charge d Compare to relative humidity chart Smaller systems with an identified volume of charge could be recovered and then the exact charge weighed in However weighing in a charge on larger system or systems without a stated amount of
24. of the office or home c In the duct work near the cooling coil 34 7 d All of the above Primarily because of the moisture found on and around the evaporator coil UV lamps should be placed near the evaporator coil UV germicidal lamps must be placed out of the line of sight to prevent damage to the eye Page 77 of 120 Rev 1 1 4 22 07 D 14 Air Filtration UA HVACR Training Manual UAHTM unit 34 D 14 b 58 Fiberglass air filters use to trap airborne matter a Tiny fiberglass particles b Continuous glass fiber 34 7 c Desiccants d Formaldehyde Continuous glass fiber is soun molded into shape to entrap larger particle of airborne particulate Tiny fiberglass particles and formaldehyde are contaminants which would need to be removed Desiccants are used to remove moisture not particulate D 14 e 59 High Efficiency Particulate Arrester HEPA filters can remove pollutants from the indoor air as small as a 20 30 microns 34 7 b 100 200 microns c 200 300 microns d 500 1000 microns The HEPA filter is capable of removing particulate bacteria and other contaminants as small as 20 30 microns D 14 f 60 Electrostatic air filters use to clean indoor air a aseries of negatively and positively charged plates 34 7 b UV b lamps c UV c lamps d All of the above Electrostatic or electronic air filters to attract particulate matter UV C lamps kill air borne organisms UV B is a distracter and does not apply to the questio
25. to atmosphere it should read 0 psig B use another gage manifold C use a micron gage D use a tire pressure gage 54 Under normal conditions mechanical ventilation can adequately remove indoor air pollution caused by A moisture B unvented gas stoves C carpets D all of the above 55 There may be as many as 100 000 different molds as long as there is food and these molds will not go away A darkness B cool temperature C moisture D stale air 56 Indoor air pollution monitoring testing equipment is available to identify the source of contamination for A carbon dioxide B carbon monoxide C ozone D all of the above 57 To be most effective UV C germicidal lamps should be placed A in bedrooms B open areas of the office or home C in the duct work near the cooling coil D all of the above 58 Fiberglass air filters use to trap airborne matter A tiny fiberglass particles B continuous glass fiber C desiccants D formaldehyde 59 High Efficiency Particulate Arrester HEPA filters can remove pollutants from the indoor air as small as A 20 30 microns B 100 200 microns C 200 300 microns D 500 1000 microns Page 37 of 120 Rev 1 1 4 22 07 60 Electrostatic air filters use to clean indoor air A aseries of negatively and positively charged plates B UV b lamps C UV c lamps D all of the above 61 filters work best to prevent air turbulence and allow for a more even loading of contaminants A Cube B
26. valve series loop system one pipe systems two pipe direct return two pipe reverse return Primary secondary pumping primary secondary common piping primary secondary circuit piping the circulator pump mixing valves in primary secondary pumping expansion tanks in primary secondary systems Radiant heating systems the human body is a radiator cold 70 what is ideal comfort the radiant system radiant heating piping tubing manifold station water temperature and direct piping Installing and starting the hydronic system install a boiler Page 21 of 120 Rev 1 1 4 22 07 install the piping wire the system fill the system fire the system Service call 1 No heat upstairs Service call 2 No heat upstairs Estimate the volume of water in the system Calculate the minimum volume for the expansion tank Fill and purge the system Reference United Association HVACR Training Manual Electricity for Heating Refrigeration and Air Conditioning Task 37 Install and service heat pumps Heat pump theory the reversing valve check valves check valves in capillary tube system check valves in systems with thermostatic expansion valves suction line accumulators bidirectional filter driers bidirectional thermostatic expansion valves Heat pump system configuration Air to air heat pumps liquid to aid heat pumps Defrost methods time initiated time terminated
27. 0 make up air AC UAJA p77 For sanitary and health concerns HVAC equipment in applications such as hospitals use 100 make up air heat or cool as needed and then exhaust that volume of air K 43 e 193 The most common method of indoor air odor control is a Electronic air filters b Disposable filters c Heap filters d Dilution with ventilation air AC UAJA p76 Filtering of air can remove some odor contamination However the best method of removing odors is to ventilate the affected air mass Page 116 of 120 Rev 1 1 4 22 07 K 43 c 194 If more air is exhausted through ventilation than is made up from fresh air inlets the building is considered a Equally pressured b Negatively pressured AC UAJA p77 c Positively pressured d To have poor air quality This building would be considered negative and it would infiltrate K 44 Exhaust Fans K 44 a 195 In kitchens where appliances may add a considerable amount of both latent and sensible heat the heating and cooling load can be reduced by the proper installation and use of a Exhaust hoods AC UAJA p 106 b Heat recovery systems c Roof top condensers d All of the above Commercial kitchen areas are a difficult area to air condition and sometimes hard to heat as well A properly installed and balanced ventilation system or exhaust hood will remove the affected air above and around the cooking equipment and have a lower impact on the balance of the controlled space K 44 c
28. 196 Correct installation and use of bathroom exhaust fans can greatly reduce the risk of a Indoor humidity issues AC UAJA p 80 b Radon gas build up c Electrical equipment malfunctions d Severe sick building syndrome Bath exhaust fans when installed properly keep the humidity level in check and prevent problems such as mold mildew and moisture damage to interior surfaces K 44 e 197 Proper ventilation in modern mechanical rooms is important because the refrigerant leaked from a system a Is corrosive b Can cause asphyxiation UAHTM 4 7 c Is flammable d Is toxic Page 117 of 120 Rev 1 1 4 22 07 Most modern refrigerant are designated by ASHREA A 1 low toxicity and non flammable The greatest concern in mechanical rooms from a refrigerant leak is the possibility of asphyxiation K 45 _ Types of Air Volume Systems K 45 a 198 The primary purpose s for the use of a Variable Air Volume VAV system is to gain operating efficiency by a Offering building zone control b Reducing the indoor blower RPM c Capitalizing on passive solar gains d All of the above AC UAJA p 365 In many applications VAV systems offer many advantages some of which are listed above K 45 b 199 The constant air volume system is less efficient than a variable air volume system because a The system always runs in the maximum heat position b The system always runs in the maximum cooling position ACUAJA p 364 c The system is always bringing i
29. 2 2 horsepower compressors will have better efficiency than 1 4 horsepower compressor If an application is likely to have varying capacity demands both circuits would operate during the greater demand period and only one compressor would operate during a lower demand period Page 115 of 120 Rev 1 1 4 22 07 K 43 Ventilation Equipment K 43 c 190 To maintain operating effectiveness and performance the air pressure in a building should be a Slightly positive to the outdoor pressure AC UAJA p77 Slightly negative to outdoor pressure Equal to the outdoor pressure Positive in the cooling season and negative in the heating season A building with a slight positive pressure to the outdoors will ex filtrate rather than infiltrate building infiltration can add 30 or more to the overall heat load Fresh or make up air will be introduced at a regulated volume to account for ex filtration o a9 K 43 b 191 Air brought into a building to replace ventilated air leaving the building is called a Infiltration air b Make up air AC UAJA p77 c Latent air d None of the above Make up air sometimes called fresh air is introduced into the duct system heated or cooled and distributed throughout the structure Make up air is necessary to provide adequate air changes per hour to maintain a healthy indoor environment K 43 d 192 Some applications such as hospital rooms require a 20 make up air b 50 make up air c 75 make up air d 10
30. 32 C 21 1 8 8 Convert 70 degrees Fahrenheit to Celsius A 17 B 21 C 34 D 38 9 An increase of temperature on a confined gas creates A no change in pressure B a decrease in pressure C an increase in pressure D creates a increase in pressure only if the gas becomes liquefied 10 What is the pressure of R 22 Refrigerant if the temperature is 32 degrees f A 9 0 psi B 30 1 psi C 57 5 psi D 298 8 psi 11 An evaporator s primary purpose is to make the refrigerated product cold absorb heat from the refrigerated product remove heat from the refrigerant cause the refrigerant to condense into liquid form 0OWLY Page 30 of 120 Rev 1 1 4 22 07 12 Residential and light commercial HVAC systems typically use A reciprocating compressors B rotary compressors C scroll compressors D any of the above 13 The condenser receives hot refrigerant vapor from the compressor and A cools the refrigerant causing a latent heat exchange B adds heat to the refrigerant causing it to condense C removes heat from the refrigerant causing a sensible heat change D both a and c 14 Residential and light commercial HVAC systems typically use A capillary metering B thermal expansion valve metering C automatic expansion valve metering D all of the above 15 The most common refrigerant used in existing modern residential or light commercial air conditioning systems is A R 12 B R 22 C R 134a D R410a 16 Refriger
31. Mixed air temperature OA Outside air OAT Outside air temperature RA Return air RAT Return air temperature Hydronic Pressure Total Head Total Head Static Head Friction Head Velocity Head Static Head Static Head Static Discharge Head Static Suction Head calculated distance above pump as positive distance below pump as negative Velocity Head VH y VH 2g g 32 2 ft sec acceleration due to gravity V Velocity of liquid Total Dynamic Head TDH DSH SSH DVH SVH TDH Total dynamic head DSH Discharge static head SSH Suction static head DVH Discharge velocity head OA Page 26 of 120 Rev 1 1 4 22 07 SVH Suction velocity head Flow Coefficient Cv rating of valve Cra Ji Q flow rate in gom H head loss pressure drop in PSI Cv flow coefficient with valve wide open equal to gpm of flow at a 1 PSI pressure drop across the valve Cv decreases as the valve closes Temperature conversions F Fahrenheit C x Z 32 5 C Celsius F 32 x J R Rankine F 460 K kelvin C 273 Ohm s Law Volts Amps x Ohms or E Ix R Watt s Law Watts Volts x Amps or P Ex l Energy formula W Pxt Formula Circle for Ohm s and Watt s Laws So ay E voltage current amps P power watts R resistance ohms W energy kWh or kilowatt hour t time hours Sum of resistance Series circuits R R R R Parallel circuits oa 1 1 1
32. R R R Sum of capacitance C Series circuits 1 1 1 1 C C C C Parallel circuits C C C C Page 27 of 120 Rev 1 1 4 22 07 Power factor calculations true power kW _ ee Power Factor apparent power kVA Cy as we Reactive Power KVAR Real Power kW Volts x Amps x 1 73 1000 Volts x Amps 1000 Reactive power kVAR VkVA kW Percent of motor load MA 0 5NPA 2 MV 0 SNPA MPV NA Measured amps NPA Nameplate amps MV Measured volts MPV Nameplate volts Transformer voltage winding calculation 3 phase apparent power kva single phase apparent power kVA load Ns E Ep x gt Np Es secondary voltage Ep primary voltage Ns number of secondary turns Ep number of primary turns Brake horsepower of a fan Bhp NPhp x MA x MN x LF NPA MPV NPhp Nameplate horsepower MA Measured amps NPA Nameplate amps FLA MV Measured volts NPV Nameplate volts LF Load factor by table Brake horsepower of a pump GPM x TDH ig Bhp x specific gravity 3960 x Eff Bip kW x Eff 0 746 Soe Total head x GPM oe Pump efficiency x specific gravity 3960 x Bhp GPM Gallons per minute TDH Total dynamic head Eff Pump efficiency kW real input power Speed Calculation Calculate new sheave diameter changing motor sheave RPM RPM sa Compression ratio R _ Absolute discharge pressur
33. Task 28 Automatic Controls and devices Overloads Overload on three phase motors Limit switches Fan switches Fan limit switches Thermostats line voltage thermostats low voltage thermostats Magnetically operated devices solenoids control transformers variable speed motor controls Electromagnetic devices relays contactors motor starters defrost timers flow switches float switches Pressure switches and controls high pressure controls low pressure controls dual pressure controls Electronic controls residential air conditioning appliances electronic thermostats solid state relays solid state starting relays solid state timers Reference United Association HVACR Training Manual Electricity for Heating Refrigeration and Air Conditioning Task 29 Electrical Troubleshooting Control circuit problems holding coils thermostats transformers control fuses pressure controls and safety devices lock out circuits Power circuit problems contactors and relay contacts Page 18 of 120 Rev 1 1 4 22 07 circuit breakers and fuses fan motors and compressor motors capacitors utility supply problems under and over voltage problems Service call 1 Blown line voltage fuse Service call 2 defective transformer Service call 3 defective contactor Service call 4 burned motor windings Service call 5 grounded compressor Reference Electricity for
34. Y Yellow D G Green To prevent room temperature overshoot most HVAC room thermostats employ a A set back module B heat anticipator C cooling anticipator D fan on auto mode Solenoid valves are A magnetically controlled B high pressured controlled C low pressured controlled D motor controlled A potential magnetic relay is controlled by the back electromotive force created by A high amperage B high resistance C the run winding D the start winding After a defrost timer control initiates a defrost period the defrost cycle may terminate by means of A time pressure or temperature B temperature only C pressure only D time only Page 51 of 120 Rev 1 1 4 22 07 145 146 147 148 149 150 A solid state starting relay is employed with fractional horse power compressors after the motor starts the relay A increases in resistance disconnecting the run winding B increases in resistance disconnecting the start winding C decreases resistance disconnecting the run winding D decreases resistance disconnecting the start winding When troubleshooting a capacitor start capacitor run motor and the technician finds the start capacitor and the run capacitor defective the technician must also check the operation of A thermal over load B current magnetic relay C compressor contactor D potential magnetic relay Most low voltage HVAC room thermostats can adjust temperature ov
35. ake up air The most common method of indoor air odor control is A electronic air filters B disposable filters C heap filters D dilution with ventilation air Page 59 of 120 Rev 1 1 4 22 07 194 195 196 197 198 199 200 If more air is exhausted through ventilation than is made up from fresh air inlets the building is considered A equally pressured B negatively pressured C positively pressured D to have poor air quality In kitchens where appliances may add a considerable amount of both latent and sensible heat the heating and cooling load can be reduced by the proper installation and use of A exhaust hoods B heat recovery systems C roof top condensers D all of the above Correct installation and use of bathroom exhaust fans can greatly reduce the risk of A indoor humidity issues B radon gas build up C electrical equipment malfunctions D severe sick building syndrome Proper ventilation in modern mechanical rooms is important because the refrigerant leaked from a system A is corrosive B can cause asphyxiation C is flammable D is toxic The primary purpose s for the use of a Variable Air Volume VAV system is to gain operating efficiency by A offering building zone control B reducing the indoor blower rpm C capitalizing on passive solar gains D all of the above The constant air volume system is less efficient than a variable air volume system beca
36. al capillary tube restriction Page 83 of 120 Rev 1 1 4 22 07 E 19 b 80 An air conditioning system with a fluctuating evaporator pressure would most likely be the result of a E 19 c a Defective circuit board b Defective AEV UAHTM 24 26 24 27 c Defective compressor d Defective capillary tube A defective circuit board compressor or capillary tube would not have an appreciable effect on fluctuating evaporator pressure The automatic expansion valve is designed to maintain a constant outlet or evaporator pressure If the low side pressure is fluctuating the AEV would be suspect 81 A system operating with a loose thermal expansion valve sensing element would cause the systems superheat to be a Too low UAHTM 24 28 b Too high c Normal d Erratic The TXV sensing element must be securely attached to the suction line for proper refrigerant metering If the element is loose and making poor contact with the suction line the result will be an overfeeding of the valve and a superheat reading that is too low E 19 d 82 Any evaporator with a pressure drop in excess of should use a thermal expansion valve with an external equalizer a 1 psig b 2 5 psig UAHTM 24 15 c 3 5 psig d 5 psig E 19 d The purpose of the external equalizer is to maintain a minimal pressure drop across the evaporator coil 83 Any system operating with a thermal expansion valve can automatically adjust to a change in the load condition In o
37. al motor overload opens what should the technician do before condemning the compressor A wait 1 hour B allow the compressor to cool down C cool the compressor down with nitrogen D replace the internal overload An air conditioning system uses a 24 volt control thermostat to maintain room temperature The same system also utilizes a low pressure switch What is the most likely purpose of this low pressure switch to cycle the compressor on when the room ambient increases to cycle the compressor on when the room ambient decrease to cycle the compressor off if the system runs low on charge to cycle the compressor off if the system is over charged Jow Page 50 of 120 Rev 1 1 4 22 07 138 139 140 141 142 143 144 A roof top air conditioning system with a defective condenser fan motor would be protected by A alow pressure safety cut out switch B ahigh pressure safety cut out switch C fan cycling pressure switch D atemperature delay switch A roof top air conditioner operating with a pressure type fan control maintains a minimum head pressure A during low ambient conditions B during high ambient conditions C during high temperature conditions D during high pressure conditions When adding central air conditioning to an existing heating system a fan relay center control or fan relay may need to be added this relay would be controlled by which thermostat lead A R Red B W White C
38. ant 410 has special characteristics including higher operating pressure a small temperature glide and is A an azeotrope B anear azeotrope C a zoetrope D acfc 17 Absorbing heat in the evaporator causes the refrigerant to A boil B get cold C sweat D turn into a liquid 18 What is the volume of an office 20 feet wide 30 feet long and 10 feet high A 60 cubic feet B 200 cubic feet C 300 cubic feet D 600 cubic feet Page 31 of 120 Rev 1 1 4 22 07 19 The nominal evaporator CFM per 1 ton of air conditioning is A 200 B 400 C 1 200 D 12 000 20 The deep vacuum is measured with a micron gauge how many microns are in 1 inch A 25 400 B 254 000 C 759 968 D none of the above 21 lf a motor operating 1725 RPM is turning a blower wheel at 500 RPM and the blower pulley is 12 what is the diameter of the motor pulley A 2 5 inches B 3 inches C 3 5 D 4 inches 22 How many watts are required to operate a 1 hp motor for a period of 1 hour A 74 6 watts B 746 watts C 7460 watts D none of the above 23 A technician must use every precaution when working with pressure electrical energy heat cold rotating machinery chemicals and when lifting heavy object to protect him her self to protect others in the area to act as a professional all of the above A B C D 24 One of the most overlooked safety devices in this industry is A safety glasses B steel toed shoes C leather gloves D se
39. artup and Charging System evacuation the vacuum pump vacuum pump oil acceptable levels of vacuum System holding charge Pre startup checklist condensing unity air handler duct system general System startup airflow through the condensing unit airflow through the air handler system pressures temperature differential across the evaporator coil evaporator superheat condenser subcooling System charging system overcharge removing excess refrigerant from the system system undercharge charging the system using manufacturers charging tables and charts Drain and replace vacuum pump oil Calibrate the gauge manifold Evacuate the air conditioning system Measure the superheat in an air conditioning system Measure the temperature differential across the evaporator coil Remove refrigerant from an operating air conditioning system Add refrigerant to an air conditioning system Reference United Association HVACR Training Manual Unit 8 10 21 38 Page 12 of 120 Rev 1 1 4 22 07 Category D Comfort Cooling Task 13 Indoor air quality Remove the source of contaminant Provide adequate air cleaning Provide adequate ventilation Mold UV light Reference United Association HVACR Training Manual Unit 34 Task 14 Air filtration Foam filters Fiberglass filters Extended surface filters Steel filters High efficiency particulate arrester filters Electrostatic air filt
40. assigned represents their flammability with the higher the number the higher the flammability F 22 Refrigerant Handling and Transporting Regulations F 22 a 94 The United States Clean Air Act Amendments of 1990 regulate the use and disposal of a CFC s b HCFC s c Bothaandb UAHTM 9 14 d Neither a or b Both CFC s and HCFC s are regulated under the authority of the Clean Air Act of 1990 and amendments F 22 a 95 The prohibition against refrigerant venting became effective a September 1 1987 b January 1 1990 c July 1 1992 UAHTM 9 14 d January 1 1996 Refrigerant venting became unlawful July 1 1992 Page 87 of 120 Rev 1 1 4 22 07 F 22 d 96 The process of removing refrigerant from a system and storage in an approved container without any further testing is known as a Recovery UAHTM 9 15 b Recycling c Reclaiming d Evacuation Recovery is simply the process of removal and storage of system refrigerant F 22 f 97 The process of used refrigerant being cleaned to meet new product specifications called ARI 700 Standard is known as a Recovery b Recycling c Reclaiming UAHTM 9 15 d Evacuation Reclaiming of refrigerant means processing refrigerant to return the compound to its original manufactured condition known as the ARI 700 purity standard F 22 b 98 Type refrigerant certification allows service on refrigeration equipment a With 5 pounds or less of charge b Hermetically sealed c Specificall
41. c systems are a circulator type pump They are not designed to increase system pressure In a typical residential light commercial hydronic heating a Provides space for the heated water to expand UAHTM 33 6 b Provides space when the water cools down c Increases the water pressure so the water does not expand d Maintains a constant water pressure equal to house pressure When water is heated the molecular structure expands this expanded volume is absorbed into the expansion tank when the water cools down it contacts and is forced back into the water system A residential hydronic heating system using three zone valve controls rated 24 Volt 50 amp each would require a transformer rated at a 20VA b 30VA c 40VA ERHAC 12 1 d 60 VA VA IXE 3valves 5 amp 1 5 amps 1 5 amps x 24 volts 36 VA minimum Page 108 of 120 Rev 1 1 4 22 07 I 33 36 d 169 When installing a hydronic heating system the use of slow opening closing zone valves allows for a The thermostat s heat anticipator to operate correctly b Zone operation without water hammering UAHTM 33 7 c Heating and cooling temperature control from the same thermostat d All of the above Water hammering in the hydronic system can be a nuisance to the customer The use of slow opening closing zones valves will eliminate water hammer noise l 37 Install and Service Heat Pumps I 37 a 170 A geothermal heat pump absorbs heat a In the evaporator in the heati
42. cal conductivity properties I 30 c 156 An electric heat system operating with a low voltage thermostat would have the heat relay wired in series with the a Blower motor b Electric heat element c Thermostat heat anticipator UAHTM 15 3 d Thermostat Y terminal One of the advantages of using a low voltage thermostat is that a heat anticipator can be incorporated I 30 c 157 Identify the safety found in electric duct heating systems a Interlock UAHTM 30 7 b Heat anticipator c Transformer d High pressure switch The interlock component prevents the duct heater element from energizing unless the indoor blower is operating which keeps the heating elements from overheating and causing a fire hazard condition I 30 h 158 Contactors and are commonly used to control the operation of the electric resistance heaters in electric furnaces a Transformer b Heat anticipator c High limit control d Sequencer ERHAC 14 7 Sequencers are often used to cycle heat elements in electric heating systems Page 105 of 120 Rev 1 1 4 22 07 I 31 Install and service gas furnace I 31 a 159 The U S Federal Trade Commission requires manufactures to provide an annual fuel utilization efficiency rating AFUE AFUE ratings are for the benefit of a The consumer UATHM 31 21 b Manufacture c The technician d The EPA The consumer can use AFUE data to shop and compare heating systems on the basis operating efficiency I 31 g 160 A high ef
43. call 3 Dirty air filter Reference United Association HVACR Training Manual Category F Refrigerant Management Task 21 Refrigerant and oil types Refrigerant types hydrocarbon refrigerants hydrochloroflourocarbon refrigerants chloroflurocarbon refrigerants hydrofluorocarbon refrigerants Blended refrigerants Ozone ozone depletion and global warming Refrigerant oils alkylbenzene oils glycols esters Safety classifications and nomenclature Reference United Association HVACR Training Manual Unit 9 Task 22 Refrigerant handling and transporting regulations Government regulations EPA Type 608 certification 410A Type Type Il Type Ill Universal Certification 410A Refrigerant recovery passive and active recovery Refrigerant recycling Refrigerant reclaiming Procedures recovering refrigerant from a system with an operative compressor recovering refrigerant from a system with a self contained recovery unit Reference United Association HVACR Training Manual Unit 9 Page 15 of 120 Rev 1 1 4 22 07 Category G Basic Electricity Task 23 Electrical theory Direct current Alternating current Ohms law Atomic theory Electron orbits Law of charges Conductors Insulators Magnetism Electrical quantities Reference HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditioning Task 24 Measuring instruments Voltme
44. ches When ever the lockout relay has opened the technician must be certain that no other reason exists for the compressor to be operating at a high amperage condition 149 When diagnosing the compressor contactor coil a proper resistance reading would be a Infinity b Zero OHMS c 45 OHMS ERHAC 11 1 d Zero OHMS to ground Page 102 of 120 Rev 1 1 4 22 07 H 29 b Some measurable resistance must be found in the coil Infinity would indicate the coil is burned out Zero ohms across the coil would indicate the coil is shorted Zero ohms to ground would indicate the coil is grounded 150 The best method to test the condition of the contacts in a compressor contactor would be H 29 b a Voltage drop test b Meg ohm test c Visual inspection ERHAC 11 1 d Micro amp test A voltage drop may be realized across the contacts and a test of resistance or amp draw may show an increase If so the contacts should be replaced Sometimes no significant change in meter readings would be detected The best way to test the contacts of an open contactor is by a visual inspection 151 When troubleshooting a fuse with a volt meter a reading of line voltage across both ends of the fuse would indicate the fuse is a Good b Open ERHAC 14 3 c Shorted d Closed A reading of line voltage at the ends of the fuse could only be obtained if an open circuit existed between the leads of the meter Service Calls Determine the problem and recom
45. cle appearance and maintenance Importance of image vehicle and personal Handling money and credit cards Background checks Parking vehicle in appropriate places courtesy and proper procedures for operating company and commercial vehicle Reference United Association HVACR Training Manual Category K Light Commercial Task 42 Roof top package units Multiple compressors Two stage gas and cool Economizer cycles Free cooling Low ambient Roofing and water proofing flashing and curbs Condensate drain Roof access and location Ladder and rigging safety Remove trash from roof Reference United Association HVACR Training Manual ARI Refrigeration and Air Conditioning 4 Edition Modern Refrigeration and Air Conditioning Electricity for Heating Refrigeration and Air Conditioning Air Conditioning Mechanical Equipment Service Manual for UAJA Task 43 Ventilation equipment Direct and indirect fire Make up air Building pressurization Outside air Smoke evacuation Reference Air Conditioning Mechanical Equipment Service Manual for UAJA Page 24 of 120 Rev 1 1 4 22 07 Task 44 Exhaust fans Kitchen hoods Rooftop Bathroom exhaust fans Fire suppression Refrigerant exhaust Reference Air Conditioning Mechanical Equipment Service Manual for UAJA United Association HVACR Training Manual Task 45 Types of air volume systems Variable air volume rooftops Constant volume Zoning systems
46. coil 153 Application Residential conditioned air system Type of Equipment Fan coil unit air cooled condensing unit Complaint No cooling Symptoms 1 Correct line voltage to furnace and condensing unit 2 Thermostat calling for cooling 3 Compressor contactor closed 4 Compressor and condenser fan motor extremely hot 5 Condenser fan motor resistance readings are C to R 6 ohms C to S 28 ohms and R to S 34 ohms Compressor run capacitor in good condition Compressor motor and bearings in good condition Condenser fan blade turns with ease Condenser fan turning slower than normal until overload cuts out oO NO low supply voltage high supply voltage shorted compressor and condenser motors too small of condensing unit COM gt Page 53 of 120 Rev 1 1 4 22 07 154 volts 155 156 157 158 159 Application Residential conditioned air system Type of Equipment Packaged air conditioner Complaint No cooling and no indoor fan operation Symptoms 1 Line voltage available to unit 2 Closing of thermostat fan switch causes no action 3 Voltage at terminals C to R on unit low voltage terminal board is 0 shorted run winding Open secondary transformer circuit shorted compressor run capacitor defected room thermostat 0UOWDLY The heating element found in electric forced air furnaces is typically made from A silver B chrome C nichrome D silver tungsten An electric hea
47. coil some systems use time and or temp to initiate the defrost cycle Other modern systems use A low pressure control connected to the indoor coil A high pressure control connected to the outdoor coil An air pressure switch sensing air pressure at the indoor coil An air pressure switch sensing air pressure at the outdoor coil UAHTM 43 25 This type of defrost initiation is more efficient as it only will defrost if a build up of frost is sensed because of an air pressure resistance increase l 37 c 173 a b C d J Soft Skills UA HVACR Training Manual UAHTM Air Conditioning Refrigeration News On Line J 38 Computer Skills J 38 c 174 When attaching a document using Microsoft Outlook e mail you must a b C d Click on the forward icon Click on the paperclip icon Microsoft Outlook Help Click on the new icon Click on the outbox icon The paperclip icon is used to attach a file to an email Page 110 of 120 Rev 1 1 4 22 07 J 38 d 175 From the following identify the most helpful internet map search engine a Adobe b Google www google com c www com d Home page Google is the only internet search engine listed above J 39 Documentation invoicing J 39 d J 39 c J 39 c 176 177 178 When completing a service call the last action taken is presenting the invoice to the customer and obtaining a signature Why is it important that all work performed
48. component which opens on a loss of pressure TOM gt lt i mo Page 46 of 120 Rev 1 1 4 22 07 115 Which symbol represents a high pressure cut out A D B E C H D C 116 The four components of a circuit are power source current path resistive load and inductive load power source current path load and switch current path load switch and light bulb load resistance current and current path COM gt Use the following schematic to answer questions 117 118 L kK 120 1 60 p a p yx Sw Lt uy R QO C 0 O o O h k OL LPC Os Q DH 117 Identify the two 2 over current devices in the schematic A qandu B qandt C tandu D qand OL Page 47 of 120 Rev 1 1 4 22 07 118 119 120 121 122 123 124 If fuse q opens which part of the circuit will still have voltage A light circuit B compressor circuit C defrost circuit D land n According to American Wire Gauge AWG the largest diameter wire is A 0000 4 0 B 2 gauge C service lead wire D 50 gauge Upon start up of a roof top air conditioning system it is found that the condenser fan motors are rotating in the wrong direction What should be done to correct the problem A replace the motor with the correct rotation motors B disconnect the power and change any two phase leads of the incoming power C reverse the directional decal on the fan blades D turn the fan blades ove
49. conductors feeding power to the device C set the meter to read amperage and clamp the meter around one of the conductors feeding power to the device D set the meter to read amperage and place the test leads on both sides of the load When testing a compressor motor with an ohmmeter what reading would be obtained if its internal over load is in the open position A run to start zero ohms B run to common zero ohms C run to start infinite ohms D run to common infinite ohms Page 44 of 120 Rev 1 1 4 22 07 109 110 111 112 The capacitor analyzer is used to measure A shorted or open capacitors and micro farad values B micro farad ratings and the capacitors power factor C open capacitors micro farad ratings and the capacitor s power factor D open and shorted capacitors micro farad ratings and the capacitors power factor What value is the meter presently set to read OFF Vv Amps Ohms AC volts DC volts VOU gt D To measure the out put of a thermocouple which setting would the meter be placed A V B 2 o 300 mV Doo V When should a mega ohmmeter never be used when the system is in a vacuum when the system is at atmospheric pressure when the system is in a positive pressure when system is charged with refrigerant 0VUOWDY Page 45 of 120 Rev 1 1 4 22 07 Use the electrical symbols chart to answer questions 113 115 114 Which symbol represents a
50. d A polyol ester oil B mineral oil C paraffin oil D polyalkalene ester oil 93 ASHRAE s Standard 34 1992 refrigerant safety group chart classifies as the least toxic and not flammable A A3 B B3 C At D B1 94 The United States Clean Air Act Amendments of 1990 regulate the use and disposal of A CFC s B HCFC s C both a and b D neither a or b 95 The prohibition against refrigerant venting became effective A September 1 1987 B January 1 1990 C July 1 1992 D January 1 1996 Page 42 of 120 Rev 1 1 4 22 07 96 97 98 99 100 101 The process of removing refrigerant from a system and storage in an approved container without any further testing is known as A recovery B recycling C reclaiming D evacuation The process of used refrigerant being cleaned to meet new product specifications called ARI 700 Standard is known as A recovery B recycling C reclaiming D evacuation Type refrigerant certification allows service on refrigeration equipment A with 5 pounds or less of charge B hermetically sealed C specifically listed D all of the above If a DC power supply of 20 volts causes 2 amps of current to flow ina circuit A the resistance of the circuit is 10 ohms B the power consumed by the circuit is 100 watts C the power consumed by the circuit is 10 watts D the resistance of the circuit is 40 ohms A is often used as a graphic representation of alt
51. d DC volts Voltage is identified by the V and the sine wave above the V indicates the voltage is alternating 111 To measure the out put of a thermocouple which setting would the meter be a b d placed V Q 300 mV V HVAC LC A normal thermocouple out put is 30 mV DC The correct setting would be 300mV DC Page 91 of 120 Rev 1 1 4 22 07 G 24 g 112 When should a mega ohmmeter never be used a When the system is in a vacuum HVAC LC b When the system is at atmospheric pressure c When the system is in a positive pressure d When system is charged with refrigerant A mega ohmmeter applies an electrical charge to the windings and a compressor should never be energized when in a deep vacuum G 25 Electrical Circuits Series and Parallel HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditionin Use the electrical symbols chart to answer questions 113 115 Page 92 of 120 Rev 1 1 4 22 07 G 25 a 113 Which symbol represents a heating thermostat a D b E HVAC LC c H d M E and M are both thermostats E opens on a rising temperature signal and M opens on a falling temperature signal E is the correct answer G 25 a 114 Which symbol represents a component which opens on a loss of pressure a D b E c H HVAC LC d M H and D are both pressure controls D is a pressure switch which op
52. d act as a learning tool If you spend time and answer the questions at the back of the texts successfully you will be successful on the UA STAR exam Page 2 of 120 Rev 1 1 4 22 07 This Study Guide also contains nearly 200 practice questions All questions are multiple choice with four possible answers All questions contain explanations for each of the correct answers The questions are designed to help you review some of the material that you will need to know when taking the exam The practice test will indicate to you whether or not you have areas of difficulty With the areas of difficulty identified you can look into references identified and update your knowledge before taking the certification test The UA STAR exam is a tough test but fair and recognized by your industry With some hard work you can be successful in passing it Good luck Page 3 of 120 Rev 1 1 4 22 07 UA Textbooks used as Reference in this Study Guide UA HVACR Training Manual HVAC Light Commercial STC Version 1 11 06 Modern Refrigeration and Air Conditioning Air Conditioning Mechanical Equipment Service Manual for UAJA Practical Heating Technology Johnson Delmar Electricity for Heating Refrigeration and Air Conditioning Thompson Delmar Learning UA Related Mathematics C1300 UA Star Equation Sheet Commercial Refrigeration for Air Conditioning Technicians Air Conditioning Refrigeration News On Line ARI Refrigeration and Air Conditioning 4 Edit
53. d technician to use in preparing for the exam It is expected that the inexperienced technician will not be able to successfully complete the exam based on the Study Guide and the information contained in the reference materials alone experience is also required It is expected that the UA STAR test candidate is the technician who has completed the UA training and has gained several years of experience in the field Many of the tasks and jobs identified in the DACUM are those that can only be learned by doing The test candidate that expects to achieve success on the UA STAR exam by merely using the Study Guide to locate information in textbooks will likely be disappointed It is recognized that even the best technician does not work in all areas of the service industry Further some knowledge can be forgotten through lack of use As such it is recommended that you study a number of UA textbooks and other resources indicated in preparing for the UA STAR exam A list is provided on the next page These texts were cited throughout the Study Guide You may wish to review the texts where you feel you need additional knowledge In addition there are many other excellent books on the market that can serve as reference for you They are far too numerous to list You may know of some of them or even own them Feel free to use them in your studies The UA and Delmar text books contain many many good questions that provide excellent practice material an
54. e Dia ew Dia x Absolute suction pressure Calculate new sheave diameter changing fan or pump sheave RPM Dia ew Dia ga x Fan Laws RPM new RPM e CFM sew CFM sa x RPM wy 2 SPrew SP x CM ew CFM sa 2 RPM e SP a Sehe new RPM a 3 BHP ew BHPyg X CEM ew CFM sa 3 RPM new old BHP x Pump Laws D GPM joy GPM og x5 old RPM GPM a x RPM old AP ew AP oa s GPM new GPM a D old 2 RPM AP ig X RPM sa 2 Dre AP x 2 3 GPM e BHP ew BHP x P GPM pa 3 Diew BHP g Bes BHPua X General Gas Law pV mRT Boyle s Law and Charles Law T p T p Charles Law with constant volume T V T V Charles Law with constant pressure P V P2V Boyle s Law with constant temperature p absolute pressure in pounds per square foot V volume in cubic feet m mass in pounds R gas constant of the particular gas foot pounds per pound per degree Rankine T absolute temperature in degrees Rankine Gas R Gas R Air 53 5 Hydrogen 765 9 Ammonia 90 5 Nitrogen 55 1 Carbon dioxide 35 1 Oxygen 48 3 Carbon 55 1 Sulfur dioxide 24 1 monoxide Page 28 of 120 Rev 1 1 4 22 07 Practice Questions Instructions The following questions are designed to give you the opportunity to practice for the UA STAR exam and to determine areas where you may need study and review
55. e refrigerant before reaching the compressor C 11 j 46 Most air conditioning tubing is brazed using as a filler material a 15 silver 7 7 b 95 5 tin antimony c 50 50 tin lead d All of the above 15 silver is often used in brazing copper tubing 95 5 50 50 are solders and are used at lower temperatures than for brazing C 11 b 47 draws the filler alloy into space between the base metals when brazing a Capillary action f7 13 b High temperature c Vacuum d Pressure Filler material is drawn into a soldered or brazed joint by capillary action created by the appropriate amount of heat applied Neither pressure nor vacuum is necessary to draw the filler material into the joint space C 12 System Evacuation Efficiency Start up and Charging UA HVACR Training Manual UAHTM unit 8 10 21 38 C 12 a 48 A vacuum pump is used to reduce a systems pressure to a 0 psia b 0 psig c 500 microns 8 10 d 5000 microns 0 psia can not be obtained 0 psig equals atmospheric pressure 5000 microns is an insufficient vacuum to thoroughly clean the system Proper evacuation should always be 500 microns or less C 12 I 49 On larger systems it is more practical to add refrigerant in the liquid phase however the technician must make certain no enters the compressor a Vapor b Contaminants c Moisture d Liquid 10 3 Moisture and other contaminants should never be allowed to enter the system Although it is much more practical t
56. e most important element s of non verbal communication is are a Spoken words b Voice inflection c Body language Customer Service Skills p 18 d All of the above Body language or motions and gestures during personal communication can speak volumes Body language often communicates more than spoken words J 40 d 180 The quality of customer service can be enhanced if the technician takes the time to a Actively listen Customer Service Skills p 27 b Explain in detail how the HVAC system works c Explain the billing process and when the bill is due d Use HVAC technical terms in explaining the work that has been completed What you say to the customer is very important but just as important is what the customer has to say to you Listen to your customer and reiterate at the conclusion of your conversations to be certain all points are clear and understood J 40 b f 181 An HVAC technician should always attempt to convey a professional image by a Clean and neat personal appearance b Clean and neat service vehicle inside and outside c Maintaining a clean and organized work site d All of the above Customer Service Skills p 13 An HVAC technician is a professional and should always present himself as professional Part of the professional image includes clean and neat personal appearance clean and neat service vehicle and maintaining an organized work space Page 112 of 120 Rev 1 1 4 22 07 J 41 Ethics and Professionalism J
57. eaaees 22 Page 6 of 120 Rev 1 1 4 22 07 Category xh SOM OKIIISint Anata Ana hasanas ah acas aoa acas aoa dace sae Na 23 rask SS COmpuiter SkillS c 0 c 0sc ezcuntcapssuessbptcinchpssuescbgzctnskgteueysbgtcuns A S 23 Task 39 Documentation invoicing ccceeeeeeeeeeeeeeneeeeeeeeeeeeeeeeeaaeeeeeeeeeeteeeeeaaees 23 Task 40 Customer relations sce secs ca lese cs ela ces eale tect eadasecs aaie a iieii 23 Task 41 Ethics and professionalism ccccccceceeeeeeeeneeeeeeeeeeeeeeeeeceeeeeeeeeeeeeeeeeeaaees 24 Category K Light Commercial oscil cial adie uhh tan inborn hide aha 24 Task 42 Roof top package units wie ie ee ee ae a a 24 Task 43 Ventilation equipment stetcccigetcortu ccc eet rite ted pe tuto tate ie eet Sart eat es 24 Mask 44 Exhaust fans cua ne ari aa i E elie ai 25 Task 45 Types of air volume SYSLOMS cccccccccccccccceeeeeceeeeeeceeceeececeeeeeeeeeeeeeeeeess 25 Task 46 Rooftop safety and NaZards cccccceceeeeeeeeeeeeeeeeeeeeeeeeeeeeneeeeeeeeeeeeeeeeeeaaees 25 Form laS gee adre ae ne ne eee er 26 Practice Questions 6 icttes cercbdatres nas oAsceed teeansSeo oneness peanebitecanet ieee ened teeeresd ooecen ed eeenstasucanees 29 Practice Questions with Explanations ccccceeeeeeeeeeeenceeeeeeeeeeeeeeeecaeeeeeeeeeeeeeeeeeeaaees 62 Page 7 of 120 Rev 1 1 4 22 07 Category A Applied Science amp Math Task 1 Matter Energy and Science of heat basics Matter solids liquids
58. ens on a rising pressure signal H is a pressure switch which opens on a falling pressure signal H is the correct answer G 25 a 115 Which symbol represents a high pressure cut out a D HVAC LC b E c H d C H and D are both pressure controls D is a pressure switch which opens on a rising pressure signal H is a pressure switch which opens on a falling pressure signal D is the correct answer G 25 a 116 The four components of a circuit are a Power source current path resistive load and inductive load b Power source current path load and switch HVAC LC c Current path load switch and light bulb d Load resistance current and current path A power source current path load and switch are 4 components of a complete circuit The type of load is not dictated resistive inductive light bulb Page 93 of 120 Rev 1 1 4 22 07 Use the following schematic to answer questions 117 118 k 120 1 60 LPC G 25 c 117 Identify the two 2 over current devices in the schematic a qandu b qandt c tandu d q and OL HVAC LC Q is a line fuse OL is a thermal overload Page 94 of 120 Rev 1 1 4 22 07 G 25 c 118 If fuse q opens which part of the circuit will still have voltage a Light circuit b Compressor circuit c Defrost circuit d LandN HVAC LC L and N would be the only remaining part of the system which still has power G 25 b 119 According to
59. ent d Electrical resistance Electronically commutated motors use a circuit board which converts 60 Hz current into DC current and then fabricates the Hz into a fully variable output The higher the frequency the greater the RPM output of the motor Voltage and resistance are not altered Page 98 of 120 Rev 1 1 4 22 07 H 27 g 135 To safely test a motor capacitor a technician should a Charge the capacitor with a low voltage b Discharge the capacitor with a resistor UAHTM 20 11 c Unplug the appliance d Remove the bleed resistor Even after the appliance has been unplugged and the capacitor removed the capacitor can still hold a very dangerous charge H 28 Automatic controls and devices H 28 a 136 If a compressor with an internal motor overload opens what should the technician do before condemning the compressor a Wait 1 hour b Allow the compressor to cool down UAHTM 25 22 c Cool the compressor down with nitrogen d Replace the internal overload The internal motor overload will close only after it cools down sufficiently Misdiagnosis can occur if testing is conducted while too hot An internal overload can not be replaced H 28 c 137 An air conditioning system uses a 24 volt control thermostat to maintain room temperature The same system also utilizes a low pressure switch What is the most likely purpose of this low pressure switch a To cycle the compressor on when the room ambient increases b To cycle the compress
60. er shooting this adjustment would be a function of A fan cycle switch B heat anticipator C programmable timer circuit D time delay relay A current sensing lockout relay is an overload device that senses the current draw of the compressor through the A lockout loop B thermo overload C lockout timer D condenser fan motor limit When diagnosing the compressor contactor coil a proper resistance reading would be A _ Infinity B Zero OHMS C 45 OHMS D Zero OHMS to ground The best method to test the condition of the contacts in a compressor contactor would be voltage drop test meg ohm test visual inspection micro amp test IoT Page 52 of 120 Rev 1 1 4 22 07 151 When troubleshooting a fuse with a volt meter a reading of line voltage across both ends of the fuse would indicate the fuse is A good B open C shorted D closed Service Calls Determine the problem and recommend a solution for the following service calls 152 Application Residential conditioned air system Type of Equipment Gas furnace with air cooled condensing unit Complaint No cooling Symptoms 1 Correct line voltage to furnace and condensing unit 2 Thermostat calling for cooling 3 Condensing unit receiving 24 volts 4 All safety controls in condensing circuitry are closed Contactor coil resistance reading is 0 ohms A low on refrigerant charge B dirty condenser C burnt out contactor coil D shorted contactor
61. ernating current A positive symbol B negative symbol C Sine wave D North pole or South pole Which of the following is true regarding current flow in a parallel circuit A current flow is equal through all branches of the circuit B the paths with higher resistance will have higher current flow C the paths with lower resistance will have higher current flow D as addition branches are added to the circuit the total current will decrease Page 43 of 120 Rev 1 1 4 22 07 102 103 104 105 106 107 108 A control transformer rated at 50 VA and a 25 volt secondary voltage should be protected with a A 0 5 amp fuse B 1 amp fuse C 1 5 amp fuse D 2amp fuse The symbol used for electrical pressure is Pe ME B P C R D P What happens to the current if the voltage in a circuit doubles and nothing else changes A the current will increase by 4 times B the current will decrease by 1 2 C the current will increase by 2 times D the current will decrease by 1 4 1 millivolt equal A 1000 volts B 100 volts C 1 1000 of a volt D 1 100 of a volt Which meter is used to test for potential A Voltmeter B Ammeter C Ohmmeter D Potentiometer To read the amperage draw from an alternating electrical device A set the meter to read voltage and place the two test leads on both sides of the load B set the meter to read amperage and clamp the meter around both
62. ers Electronic air filters Reference United Association HVACR Training Manual Unit 34 Task 15 Humidity and Humidification Humidifiers freestanding self contained humidifiers Duct mounted humidifiers Reference United Association HVACR Training Manual Unit 34 Page 13 of 120 Rev 1 1 4 22 07 Task 16 Installing and troubleshooting air quality devices Fresh air and ventilators Troubleshooting and maintaining air quality devices Reference United Association HVACR Training Manual Unit 34 Category E Comfort Cooling Troubleshooting Task 17 Evaporator and condenser fan motor problems Improper airflow Improper motor lubrication Improper pulley alignment Improper belt tension Reference United Association HVACR Training Manual Commercial Refrigeration for Air Conditioning Technicians Electricity for Heating Refrigeration and Air Conditioning Task 18 Refrigerant charge related problems System pressure readings Complete loss of refrigerants charge System contamination Reference United Association HVACR Training Manual Task 19 Evaluating the metering device Evaluating the capillary tube Evaluating the automatic expansion valve Evaluating the thermostatic expansion valve Reference United Association HVACR Training Manual Unit 24 Page 14 of 120 Rev 1 1 4 22 07 Task 20 Troubleshooting steps Service Call 1 System overcharge Service call 2 System undercharge Service
63. eter to read amperage and clamp the meter around one of the conductors feeding power to the device HVAC LC d Set the meter to read amperage and place the test leads on both sides of the load A clamp on amp meter is used by opening the jaws and placing 1 only conductor feeding the load inside then close the jaws read amperage with the load operating The test leads are not used G 24 c 108 When testing a compressor motor with an ohmmeter what reading would be obtained if its internal over load is in the open position a Run to start zero ohms b Run to common zero ohms c Run to start infinite ohms d Run to common infinite ohms HVAC LC Run to start should equal the total sum of the run winding resistance plus the start winding resistance e 3 7 10 Run to common is open producing an infinite resistance Page 90 of 120 Rev 1 1 4 22 07 G 24 e 109 The capacitor analyzer is used to measure a b C d Shorted or open capacitors and micro farad values HVAC LC Micro farad ratings and the capacitors power factor Open capacitors micro farad ratings and the capacitor s power factor Open and shorted capacitors micro farad ratings and the capacitors power factor A capacitor analyzer does not measure power factor It does measure micro farad values and identifies open or shorted capacitors G 24 f 110 What value is the meter presently set to read a Amps b Ohms c AC volts HVAC LC
64. f latent heat 1 Latent heat of fusion when liquid becomes a solid or when a solid becomes a liquid 2 Latent heat of vaporization when a liquid becomes a vapor or when a vapor becomes a liquid C F 32 C 21 use formula page 23 A 1 c 1 8 8 Convert 70 degrees Fahrenheit to Celsius a 17 b 21 UAHTM 1 13 c 34 d 38 C F 32 C 21 1 8 Page 64 of 120 Rev 1 1 4 22 07 A 2 The Refrigeration Process UA HVACR Training Manual UAHTM unit 3 P T Chart A 2 g 9 An increase of temperature on a confined gas creates a No change in pressure b A decrease in pressure c Anincrease in pressure UAHTM 3 5 d Creates a increase in pressure only if the gas becomes liquefied An increase of heat applied to a confined gas would bring about an increase of pressure on that gas Example a can partially filled with gasoline sitting in the sunlight would increase in temperature because of solar heat gain that increase of temperature would cause the molecules of the liquid and vapors in the gas can to expand this expansion in a confined space would bring about an increase in the pressure inside of the gas can A 2 g 10 What is the pressure of R 22 Refrigerant if the temperature is 32 degrees f a 9 0 psi b 30 1 psi c 57 5 psi UAHTM f 3 15 d 298 8 psi See pressure temperature chart A 2 a 11 An evaporator s primary purpose is to a Make the refrigerated product cold b Absorb heat from the refrigerated product UAHTM 3 7 c Remove
65. f 120 Rev 1 1 4 22 07 187 188 189 190 191 192 193 An optional arrangement added to a roof top air conditioning system which has a motorized damper and opens when the room thermostat calls for cooling and outdoor temperature and humidity conditions are met is called A an economizer B heat recovery C free ventilation D desiccant cooling Roof top air conditioners typically are mounted on top of a roof curb to help provide a leak proof connection to the roof The roof curb is generally high A 2 4 inches B 6 10 inches C 12 15 inches D 24 30 inches Many roof top heating air conditioning systems are 2 stage heating or 2 stage cooling or both The primary purpose for this is A to allow a wider application of equipment B to allow for fluctuating loads C less costly to build equipment D to use smaller gas lines and refrigerant lines To maintain operating effectiveness and performance the air pressure ina building should be A slightly positive to the outdoor pressure B slightly negative to outdoor pressure C equal to the outdoor pressure D positive in the cooling season and negative in the heating season Air brought into a building to replace ventilated air leaving the building is called A infiltration air B make up air C latent air D none of the above Some applications such as hospital rooms require A 20 make up air B 50 make up air C 75 make up air D 100 m
66. f the ignition transformer with an output voltage of 10 000 volts 164 When servicing the oil burner that repeatedly locks out the technician tests the Cad Cell In the presence of light the correct OHM reading should be a 0 OMHS b 600 to 1000 OMHS UAHTM 32 9 c 50 000 to 100 000 OMHS d Infinity The primary control on the oil burner will lock out after a preset time usually 45 120 seconds unless the cad cell detects the light from ignition which causes the cad cells resistance to decrease from approximately 100 000 ohms in the absence of light to 600 1000 ohms in the presence of light 165 A standard oil burner nozzle identified as 80 degrees of angle and 1 00 GPH would deliver approximately how many BTUs per hour a 40 000 BTUs b 80 000 BTUs c 100 000 BTUs d 140 000 BTUs RACT 32 6 The nozzle identified as 1 00 means 1 gallon of fuel can flow through the nozzle in 1 hour of operation 1 gallon of fuel oil contains about 140 000 BTU s Page 107 of 120 Rev 1 1 4 22 07 33 36 Install and service hydronic heat I 33 36 a 166 non positive displacement pumps because I 33 36 a 167 system the expansion tank I 33 36 d 168 Centrifugal pumps used in hydronic heating are considered a They do not add significant pressure to the system UAHTM 33 8 b Because they do add significant pressure to the system c Because the pistons are very small d None of the above Centrifugal pumps are used in hydroni
67. ficiency gas furnace utilizing hot surface ignition HIS will enter into lockout mode if ignition is not detected a 2 seconds or less b 4 to 11 seconds UAHTM 31 19 31 22 c 15 to 20 seconds d 30 seconds Ignition circuit boards used on HSI systems will typically lockout after 4 11 seconds if ignition is not detected l 31 f 161 High efficiency furnaces use plastic vent piping because a Acidic flue gases b Lower flue temperatures c Condensation of flue gases d All of the above UAHTM 31 25 All of the above are true of high efficiency furnace venting The flue gases are acidic the plastic pipe is not affected by the acid The flue gases are lower in temperature permitting the use of the less costly plastic vent pipe Flue gases will condense in the secondary heat exchanger the plastic pipe allows for tight leak proof joints and seams l 31 f 162 A technician uses which instrument to measure gas service and manifold pressure a Anemometer b Draft gauge c Water manometer UAHTM 31 3 d Manifold gauge Gas pressure can only be accurately be measured by a water manometer Page 106 of 120 Rev 1 1 4 22 07 32 Install and service oil furnaces I 32 h 163 When servicing the ignition transformer of an oil furnace correct secondary 1 32 i I 32 h voltage would be 120 volts b 600 volts c 6 000 volts d 10 000 Volts UAHTM 32 14 The intense arc necessary to ignite fuel oil is produced by the secondary side o
68. ge to the atmosphere it should read 0 psig 11 4 b Use another gauge manifold c Use a micron gauge d Use a tire pressure gauge The proper method to test the accuracy of manifold gauges is to open the gauge to atmospheric pressure it should read 0 psig If not adjust to 0 psig Page 76 of 120 Rev 1 1 4 22 07 D Comfort Cooling D 13 Indoor Air Quality UA HVACR Training Manual UAHTM unit 34 D 13 c 54 Under normal conditions mechanical ventilation can adequately remove indoor air pollution caused by D 13 d a Moisture b Unvented gas stoves c Carpets d All of the above f 34 1 Indoor air pollution can be greatly reduced if not eliminated by adequate ventilation 55 There may be as many as 100 000 different molds as long as there is food and D 13 a these molds will not go away a Darkness b Cool temperature c Moisture 34 4 d Stale air Molds account for a vast amount of the indoor air contaminants The primary biological requirements to sustain molds are food and moisture Other factors are of less importance 56 Indoor air pollution monitoring testing equipment is available to identify the source of contamination for D 13 e a Carbon dioxide b Carbon monoxide c Ozone d All of the above 34 5 All of these and many other contaminants can be specifically tested for with modern equipment 57 To be most effective UV C germicidal lamps should be placed a In bedrooms b Open areas
69. h a and b One of the most popular motors used in the HVAC industry with moderate starting torque and good running efficiency is the motor A capacitor start capacitor run B shaded pole C permanent split capacitor D three phase Identify the most rugged and reliable motor used in the industry which operates without the assistance of start components A induction motor B permanent split capacitor motor C three phase motor D shaded pole Page 49 of 120 Rev 1 1 4 22 07 132 133 134 135 136 137 Identify the difference between a three pole contactor and a three pole magnetic starter A a contactor has an overload circuit B a magnetic starter has an overload circuit C amagnetic starter has a solenoid coil D acontactor has solenoid coil In identifying the common start run terminals of a split phase motor terminal A to B 10 ohms terminal A to C 3 ohms and terminal B to C 7 which terminal is common A terminal A B terminal B C terminal C D ground terminal Electronically commutated motors alter the output drive speed This is accomplished by altering A electrical frequency B electrical voltage C electrical current D electrical resistance To safely test a motor capacitor a technician should A charge the capacitor with a low voltage B discharge the capacitor with a resistor C unplug the appliance D remove the bleed resistor If a compressor with an intern
70. ically bond to form a new molecule Zeotropes also are called refrigerant Blends Although R 410a is not an azeotrope chemically under pressure of the a c system it performs as an azeotrope A 2 d 17 Absorbing heat in the evaporator causes the refrigerant to a Boil UAHTM 3 7 b Get cold c Sweat d Turn into a liquid Absorbing heat is the purpose of the evaporator Heat added to a low pressure low temperature liquid refrigerant causes the refrigerant to boil The refrigerant does not get cold The low temperature refrigerant may cause the evaporator to sweat the refrigerant itself must remain absolutely dry A 3 Applied HVAC Math UA HVACR Training Manual UAHTM UA STAR Equation Sheet Related Mathematics A 3 c 18 What is the volume of an office 20 feet wide 30 feet long and 10 feet high a 60 cubic feet b 200 cubic feet c 300 cubic feet d 600 cubic feet RM p 46 fig 3 4 20 x 30 x 10 600 Cu Ft A 3 b 19 The nominal evaporator CFM per 1 ton of air conditioning is a 200 b 400 UAHTM 37 26 c 1 200 d 12 000 In a typical a c system for every 12 000 BTU s of cooling produced a supply of 400 CFM is needed to move the air throughout the ductwork and structure A 3 f 20 The deep vacuum is measured with a micron gauge how many microns are in 1 inch Page 67 of 120 Rev 1 1 4 22 07 a 25 400 UAHTM 8 8 b 254 000 c 759 968 d None of the above This is a measurement equivalency
71. id exerts pressure downward and outward the force of gravity would prevent liquid from exerting pressure upward A 1 b 4 The Law of Conservation of Energy states that energy is neither created nor destroyed but a Is renewable b Can be converted from one form to another UAHTM2 8 c Is not renewable d Bothaandb The Law of Conservation of Energy states that energy is neither created nor destroyed It also states that energy can be converted from one form to another such as from electrical energy to mechanical energy or to heat energy or vise versa Page 63 of 120 Rev 1 1 4 22 07 A 1 d 5 Dalton s Law of Partial Pressures shows that the total pressure of a confined mixture of gases is a An average of all the gases combined b The least pressure of each of the gases c The sum ofall the gases UAHTM f 2 7 d Not measurable Dalton s Law states the total pressure of multiple gases gas a gas b gas c the sum of all the gases A 1 c 6 Heat flow is always in the direction of a Hot to cold UAHTM 2 9 b Cold to hot c Lower to higher d Higher to lower Regardless of the quantity of heat heat flow is always in the direction of the warmer substance to the cooler substance Answers c and d refer to the stratification of heat A 1 c 7 Latent heat is experienced a When the earths temperature decreases b Water turns to steam c When ice melts d Bothb amp c UAHTM 1 7 There are 2 forms or examples o
72. identified by A low suction pressure B low system capacity C high superheat D all of the above 85 If an air conditioning compressor is allowed to operate with a low refrigerant charge the compressor is likely A to draw higher than normal amperage B to make excessive noise C to be very hot D all of the above 86 An air conditioning system using a TXV and operating with an overcharge of refrigerant can be identified by A high discharge pressure B higher than normal suction pressure C low system capacity D all of the above 87 An overcharged air conditioning system using a capillary tube metering device would have high head pressure have high suction pressure allow liquid refrigerant to enter the compressor all of the above 88 A properly charged air conditioning system with a dirty air filter could frost back to the compressor cause the condenser fan to overheat cause ice buildup on the condenser all of the above VUOWUF gt F DOWD Page 41 of 120 Rev 1 1 4 22 07 89 CFC refrigerants contain which is considered the most harmful to the ozone layer A fluorine B chlorine C hydrogen D carbon 90 HCFC based blends are considered A short term replacements B long term replacements C ozone friendly D inefficient 91 Stratospheric ozone is considered good ozone because it filters out A Air pollution B UV b light rays C UV c light rays D CFC s 92 HFC 134a refrigerant uses synthetic oil calle
73. igerant A liquid line B high pressure line C discharge line D low pressure line 46 Most air conditioning tubing is brazed using as a filler material A 15 silver B 95 5 tin antimony C 50 50 tin lead D All of the above Page 35 of 120 Rev 1 1 4 22 07 47 draws the filler alloy into space between the base metals when brazing A Capillary action B High temperature C Vacuum D Pressure 48 A vacuum pump is used to reduce a systems pressure to A 0 psia B 0 psig C 500 microns D 5000 microns 49 On larger systems it is more practical to add refrigerant in the liquid phase however the technician must make certain no enters the compressor A vapor B contaminants C moisture D liquid 50 What is the superheat of an R 22 air conditioning system if the evaporator boiling point temperature is 40 degrees f and the suction line temperature is 52 degrees f A 12 degrees f B 30 degrees f C 62 degrees f D 92 degrees f 51 When installing a central air conditioning system the entire refrigerant charge is typically A added by the technician B shipped and held in the evaporator C shipped and held in the condensing unit D recovered before evacuation 52 Vacuum pump oil must be changed on a regular basis because it can become very contaminated with A CFC s B Moisture C HCFC s D All of the above Page 36 of 120 Rev 1 1 4 22 07 53 To calibrate a gauge manifold a technician should A open the gauge
74. ing with an overcharge of refrigerant can be identified by a High discharge pressure b Higher than normal suction pressure c Low system capacity d All of the above UAHTM 29 12 An overcharged system will cause high discharge and suction pressure as well as low sub cooling all of which lead to low system capacity E 20 a 87 An overcharged air conditioning system using a capillary tube metering device would a Have high head pressure b Have high suction pressure c Allow liquid refrigerant to enter the compressor d All of the above UAHTM 29 12 All of the above are indicative of an overcharged cap tube system Page 85 of 120 Rev 1 1 4 22 07 E 20 c 88 A properly charged air conditioning system with a dirty air filter could a Frost back to the compressor UAHTM 29 13 b Cause the condenser fan to overheat c Cause ice buildup on the condenser d All of the above A dirty air filter will reduce the amount of heat absorbed by the evaporator this can cause frost build up on the evaporator as well as the compressor No effect would be realized by the condenser fan and although the condenser temperature would likely be reduced by the dirty filter the condenser temperature would still remain well above the freezing point F Refrigerant Management F 21 Refrigerant and Oil Types UA HVACR Training Manual UAHTM unit 9 F 21 a 89 CFC refrigerants contain which is considered the most harmful to the ozone layer a Fluorine b Chlo
75. intended load A 2 times B 3 times C 5times D 7 times Page 61 of 120 Rev 1 1 4 22 07 Practice Questions with Explanations Instructions The following questions are designed to give you the opportunity to practice for the UA STAR exam and to determine areas where you may need study and review Once you have answered the practice questions you can check your answers using a separate document from the UA This document contains explanations for most of the correct and incorrect answers Task links are also provided with each question These links direct you to specific areas of the DACUM From there you can locate the UA text to use for reference on your specific area of interest Page 62 of 120 Rev 1 1 4 22 07 A Applied Science amp Math A 1 Matter Energy and Science of heat basics UA HVACR Training Manual UAHTM unit 1 amp 2 A 1 a 1 Matter is commonly explained as a substance that occupies space and has a Mass UAHTM 2 1 b Solid c Liquid d Gas Mass is correct solid liquid and gas are merely the states or forms of matter A 1 a 2 Solid mass exerts pressure a In all directions b Downward only UAHTM 2 2 f 2 1 c Down and outward d All of the above A vapor or gas exerts pressure in all directions a solid can only exert pressure in a downward manner A 1 a 3 Liquid mass exerts pressure a Downward only b In all directions c Down and outwardUAHTM 2 2 f 2 2 d All of the above A liqu
76. ion amp 5 Edition www hanford gov fire safety extingrs htm fetypes www chp edu besafe adult 02frostbite ohp base hs www osha gov www ansi org Page 4 of 120 Rev 1 1 4 22 07 CONTENTS OI AATA m D AEAEE aie dante A EE EEA AA EE EEEE EE T EEEE 2 UA Textbooks used as Reference in this Study Guide cccecceeeeeeeeeeeeeeeeeeeeeeeeeeeees 4 CONTENTO oaan A 5 Category A Applied Science amp Math sssssssssssssesseessessesssessessssssessssssseeeeeeeees 8 Task 1 Matter Energy and Science of heat basics cccccccccccccccceceeeeeeeeeeeeeeeeeeees 8 Task 2 The Refrigeration Process sige ices ceeds ieee este vee edie tadeteed re edi caltees tel uduieds utes 8 Task 3 Applied HVAC math ccccccccccccccccceccecceeceeeeeeeeeeeeeeeeeeeeeeeceeeeeeeeeeeeeeeeeeseeeneess 9 Category Bi Saf ty eri esi sre ce er ee EE ci ii ec el EEE EAE EEEE E an ia E 9 Task 4 Personal safety os as a a Sata At AO St a ta Se 9 lask 5 Electrical safety drii ar aaa a a a a a aE 9 Task GL mI Salo casas iaaa E EA A 10 Task 7 Tools equipment and material Safety ccccccccccccccccceeeeeeeeeeeeeeeeeeeeeeeeeees 10 Fask 8 Firstald Pee RPee eee nPreEe PRPECRE E TAPED PRPIERE TREC RE Ni 10 task 9 AQENCIE S rinine areae aeie anae ai e i aei ii ieia 10 Category C INStAllAatOM ics2 i02s0520setesi2ededsoseedadedbinedadeeidedadsbidetadenidedadsdidedadeninedadeeieeeBes 11 Task 10 Unit location and the air distribution system
77. ip icon C click on the new icon D click on the outbox icon From the following identify the most helpful internet map search engine A Adobe B Google C www com D Home page When completing a service call the last action taken is presenting the invoice to the customer and obtaining a signature Why is it important that all work performed is accurately described on the invoice A to reference details at a later date B to identify warranty parts or service C to provide service details in written communication form D all of the above Service technicians must be thorough in order to prevent a breakdown in communication that results in lost time money Which of the following is not part of the required invoice information A date of repair B actual labor C total cost D original supplier of equipment What measures can service technicians take to ensure that work orders are complete A write legibly B do not rush C explain the work order to the customer and ask if they have any questions D all of the above The most important element s of non verbal communication is are spoken words voice inflection body language all of the above TODD Page 57 of 120 Rev 1 1 4 22 07 180 181 182 183 184 185 186 The quality of customer service can be enhanced if the technician takes the time to actively listen explain in detail how the HVAC system works explai
78. ir Conditioning H 27 b 127 Because most induction motors require additional starting torque are implemented a Start and run capacitor b Start windings ERHAC 9 4 c Shaded pole circuits d Three phase winding Start windings are typical of induction motors to momentarily increase the torque during starting H 27 c 128 Shaded pole motors can most easily be identified by a A heavy copper band ERHAC 9 4 b A start capacitor c Arun capacitor d Both start and run capacitor Shaded pole motors can easily be identified by the heavy gauge copper band located around the stator of the motor H 27 d 129 The primary application for shaded pole motors would be a When low start torque is required b When low run torque is required c When three phase power is not available d Both A and B ERHAC 9 4 Shaded pole motors are very common throughout the industry and are used in low torque applications H 27 d 130 One of the most popular motors used in the HVAC industry with moderate starting torque and good running efficiency is the motor a Capacitor start capacitor run b Shaded pole c Permanent split capacitor ERHAC 9 7 d Three phase PSC motors provide a moderate torque while maintaining good running efficiency The capacitor start capacitor run motor is less efficient The 3 phase motor is high torque Page 97 of 120 Rev 1 1 4 22 07 H 27 e 131 Identify the most rugged and reliable motor used in the industry which operates withou
79. is accurately described on the invoice a To reference details at a later date b To identify warranty parts or service c To provide service details in written communication form d All of the above Tech to Tech Chapter 9 For all parties concerned complete and accurate documentation should be completed on all invoices Service technicians must be thorough in order to prevent a breakdown in communication that results in lost time money Which of the following is not part of the required invoice information a Date of repair b Actual Labor c Total cost d Original supplier of equipment Customer Service Skills p 47 Date of repair actual labor and the total cost are all very important to have listed on the invoice The identification of the equipment supplier is not necessary What measures can service technicians take to ensure that work orders are complete a Write legibly b Do not rush c Explain the work order to the customer and ask if they have any questions d All of the above Customer Service Skills p 47 All of the above will help to assure completeness of invoices Writing legibly helps yourself to double check your own Page 111 of 120 Rev 1 1 4 22 07 documents as well as the customer will be able to understand what you have written and service you have performed Further a well written clear concise and legibly written invoice is a display of professionalism J 40 Customer Relations J 40 c 179 Th
80. l of pressure during low ambient conditions 140 When adding central air conditioning to an existing heating system a fan relay center control or fan relay may need to be added this relay would be controlled by which thermostat lead H 28 f a R Red b W White c Y Yellow d G Green UAHTM 42 10 Typical color code R power red Ws heat white Y cooling yellow or blue if no yellow is present G fan Green 141 To prevent room temperature overshoot most HVAC room thermostats employ a a Set back module b Heat anticipator ERHAC 12 2 c Cooling anticipator d Fan ON AUTO mode The heat anticipator is a small resistive coil or resistor which applies heat to the thermostat sensing element When properly adjusted it causes the room thermostat prematurely open the burner circuit allowing the blower to remove the final quantity of heat in the heat exchanger and meeting the room thermostat set point Page 100 of 120 Rev 1 1 4 22 07 H 28 g 142 Solenoid valves are H 28 h a Magnetically controlled ERHAC 12 6 b High pressured controlled c Low pressured controlled d Motor controlled Solenoid valves are directly operated by electro magnetic coils The control signal could come from anytime temperature or pressure sensing device 143 A potential magnetic relay is controlled by the back electromotive force created by H 28 h a High amperage b High resistance c The run winding d
81. lf contained breathing apparatus 25 Wearing metal jewelry can be most harmful because of frost bite shock or electrical burn magnetic electrical energy electrical ground fault 0OWDLY Page 32 of 120 Rev 1 1 4 22 07 26 Whenever possible a technician should Lock out Tag out the electrical service panel before working on system to prevent the unit starting up automatically electrical shock to prevent others from starting the system all of the above MOOD 27 The third wire or ground wire is utilized to prevent A electrical shock from defective equipment B the use of some extension cords C high voltage from reaching electrical tools D counter emf 28 A technician should never use an extension cord unless it has been plugged intoa A GFCI B breaker panel C acircuit with at least 20 amps of service D all of the above 29 If you encounter a fire with a source of flammable liquids A you must use a class a fire extinguisher B you must use a class b fire extinguisher C you must use a class c fire extinguisher D you must use a class d fire extinguisher 30 Multi purpose fire extinguishers rated A B C can be used on A flammable liquids B ordinary combustibles C electrical equipment D all of the above 31 When using a fire extinguisher always aim A at the base of the fire B in front of the fire C at the top of the fire D all of the above
82. lgaecides c Drained regularly d All of the above 34 12 During the cooling season humidifiers should be shut down Furthermore regular cleaning and chemical treating is necessary D 16 b 68 To kill mold and algae and to prevent them from contaminating the area some manufacturers use a UV lights 34 12 b Radon c Fungicides d All of the above UV lamps are used to kill mold and algae Radon and fungicides do not apply to this question Page 80 of 120 Rev 1 1 4 22 07 E Comfort Cooling Troubleshooting E 17 Evaporator and Condenser Fan Motor Problems UA HVACR Training Manual UAHTM Commercial Refrigeration for Air Conditioning Technicians CRACT Electricity for Heating Refrigeration and Air Conditioning EHRAC E 17 a 69 The required condenser air flow is approximately a 400 CFM per ton b 600 CFM per ton c 800 CFM per ton d 1000CFM per ton CRACT p36 The nominal air flow requirement is 1000 CFM on the condenser side of the system The condenser side must not be confused with the evaporator portion of the system where 400 CFM is the nominal requirement E 17 a 70 A dirty condenser prevents the rejection of heat and causes a Low head pressure b High head pressure CRACT p36 37 c Low suction pressure d High suction pressure When heat from the condenser cannot be rejected system pressure will be increased Head pressure will have the most dramatic increase but depending on other factors suction pressure as well can
83. mend a solution for the following service calls H 29 e 152 Application Residential air conditioning system Type of Equipment Gas furnace with air cooled condensing unit Complaint No cooling Symptoms aop 1 Correct line voltage to furnace and condensing unit 2 Thermostat calling for cooling 3 Condensing unit receiving 24 volts 4 All safety controls in condensing circuitry are closed 5 Contactor coil resistance reading is 0 ohms Low on refrigerant charge Dirty condenser Burnt out contactor coil Shorted contactor coil ERHAC 14 Practice service calls Page 103 of 120 Rev 1 1 4 22 07 The contactor coil should have a measurable amount of resistance approx 50 ohms A reading of O zero ohms indicates a shorted coil The condensing unit will not energize until the coil is replaced H 29 c 153 Application Residential conditioned air system Type of Equipment Fan coil unit air cooled condensing unit Complaint No cooling Symptoms 1 Correct line voltage to furnace and condensing unit 2 Thermostat calling for cooling 3 Compressor contactor closed 4 Compressor and condenser fan motor extremely hot 5 Condenser fan motor resistance readings are C to R 6 ohms C to S 28 ohms and R to S 34 ohms 6 Compressor run capacitor in good condition 7 Compressor motor and bearings in good condition 8 Condenser fan blade turns with ease 9 Condenser fan turning slower than normal until overload cuts out a Low
84. n Page 78 of 120 Rev 1 1 4 22 07 D 14 c 61 filters work best to prevent air turbulence and allow for a more even loading of contaminants a Cube b Fiberglass c Pleated 34 7 34 16 d HEPA Cube Fiberglass and HEPA filters have a tendency to restrict air flow as the filter loads up Pleated filters provide a much great surface area therefore creating much less air turbulence as the filter begins to fill D 15 Humidity and Humidification UA HVACR Training Manual UAHTM unit 34 D 15 a 62 The recommended humidity level in homes or buildings is D 15 a a No more than 20 b 20 40 c 40 60 34 9 d At least 70 For most people 40 60 relative humidity is very comfortable less than 40 is too dry and greater than 70 is too wet 63 Duct mounted bypass humidifiers allows air from the supply duct to D 15 a a Flow directly to the return air duct b Pass through a media c Be heated before entering the humidifier d Allofthe above 34 9 A by pass humidifier is simply a connection from the supply air side to the return air side of the duct system In this type system the heated air from the furnace passes through the humidifier media absorbs humidity and then is recycled through the furnace allowing the treated air to mix into the return air and be distributed throughout the structure via the supply air duct 64 Humidifiers should only operate a When the air handler blower is ope
85. n D 1000 CFM per ton 70 A dirty condenser prevents the rejection of heat and causes A low head pressure B high head pressure C low suction pressure D high suction pressure 71 A condenser fan motor with sleeve bearings should be lubricated A 2 times per year B 3 times per year C 4 times per year D once per month 72 Improper blower pulley alignment can cause A unnecessary wear B erratic speed C premature belt failure D all of the above 73 V Belt tension should be set to about A 2inch B 1 inch C 1 Yinches D 2 inches 74 To add refrigerant to a partially charged air conditioning system a technician should read the manifold gages and then compare to a pressure temperature chart consult with the manufacturer recover the existing charge and weigh in the correct charge compare to relative humidity chart Page 39 of 120 Rev 1 1 4 22 07 0OWLY 75 Starting up an air conditioning system with the indoor temperature at 85 degrees f and the Rh at 70 would be considered A an excessive load B anormal load C alight load D none of the above 76 During a complete loss of charge condition with a leak on the systems low side and the systems low pressure cut out control has opened the technician must consider A finding and repairing the leak B contaminant in the system C the compressor will not start until the system is recharged D all of the above 77 After a system evacuation can cause a micron gage to ri
86. n outside air d The system is always exhausting inside air Constant air volume systems are operated in the max cool position the air is then tempered in necessary K 45 c 200 When zoning a building for the purpose of climate control zones are generally divided into areas by a Floors 1 floor 2 floor b Exposure north side south side etc c Occupancy number of people type of activity d All of the above AC UAJA p 353 Due to stratification of air warm air rises to a higher level zoned systems would separate one floor from another Also exposure considerations can be considered such as one wall has many square feet of window area and an adjacent wall has no window exposure in this case separate zones for these two areas would deliver greater comfort and efficiency Finally occupancy the number of people and the type of activity provide a varying heating and cooling demand and should be zoned accordingly Page 118 of 120 Rev 1 1 4 22 07 K 46 Roof Top Safety and Hazards K 46 b 201 K46 g 202 K 46 b 203 K 46 b 204 When working on an upper floor or a roof top of a building the top of the ladder should extend above the top edge of the roof by at least a 1 foot b 3 feet UAHTM fig 4 17 c 5 feet d Never use an extension ladder on a roof top An extension ladder should extend at least 3 feet above the top edge of the roof to serve as a hand hold and to aid in stability of the person using the ladder
87. n the billing process and when the bill is due use HVAC technical terms in explaining the work that has been completed COM gt An HVAC technician should always attempt to convey a professional image by A clean and neat personal appearance B clean and neat service vehicle inside and outside C maintaining a clean and organized work site D all of the above If a technician determines he can not keep a scheduled customer appointment he should travel as fast as possible to get there as soon as possible call the customer to keep them informed of your delay do nothing the customer expects service people to be late call the customer and tell them you have been on a more important service call DOWD Background checks are necessary to disclose employee history associated with A criminal records B credit reports C drug testing D all of the above Which of the following would be a display of professionalism A work uniform with company logo B being punctual C use of good people skills D all of the above Parallel compressors are piped into a system in such a manner that A the discharge lines are connected to a common manifold B the suction lines are connected to a common manifold C the liquid lines are connected to a common manifold D both a and b E An advantage of the parallel compressor systems would be load matching higher efficiency less compressor cycling all of the above Jow Page 58 o
88. ng mode UAHTM 43 1 b In the condenser in the heating mode c In the condenser during the cooling mode d None of the above Heat transfer is always in the direction of hot to cold The heat medium water is typically 40 to 50 degrees the hot source the refrigerant temperature in the evaporator would typically be about 20 degrees the cold source thus the heat would leave the 50 degree water and be absorbed into the 20 degree refrigerant 1 37 b 171 On a split system air source heat pump operating with an outdoor ambient of 30 degrees f the refrigerant boiling temperature would be approximately a 10 degrees b 10 degrees UAHTM 43 15 c 30 degrees d 70 degrees Approximately 20 degrees of temperature difference is maintained between the heat medium 30 degrees and the refrigerant boiling temperature 10 Page 109 of 120 Rev 1 1 4 22 07 l 37 d 172 A coaxial heat exchanger used on geothermal heat pumps allows a b C d Water to flow in one direction and refrigerant in the opposite direction UAHTM 44 4 Water and refrigerant to flow in the same direction Water to flow only if the water check valve is open None of the above A coaxial heat exchanger is a smaller tube refrigerant inside a larger tube water The two mediums travel through the heat exchanger in opposite directions allowing for a maximum amount of heat transfer During the heating mode air source heat pumps must periodically defrost the outdoor
89. nt will decrease Apply ohms law G 23 c 102 A control transformer rated at 50 VA and a 25 volt secondary voltage should be protected with a a 0 5 amp fuse b 1 amp fuse c 1 5 amp fuse d 2 amp fuse HVAC LC Apply ohms law G 23 c 103 The symbol used for electrical pressure is a E HVAC LC b I c R d P E voltage pressure current or amperage R Ohms or resistance P power or watts G 23 c 104 What happens to the current if the voltage in a circuit doubles and nothing else changes a The current will increase by 4 times b The current will decrease by 1 2 HVAC LC c The current will increase by 2 times d The current will decrease by 1 4 Apply ohms law Page 89 of 120 Rev 1 1 4 22 07 G 23 j 105 1 millivolt equals a 1000 volts b 100 volts c 1 1000 of a volt HVAC LC d 1 100 of a volt 1 millivolt is equal to 1 1000 of a volt G 24 Measuring Instruments HVAC Light Commercial STC Version 1 11 06 G 24 a 106 Which meter is used to test for potential a Voltmeter HVAC LC b Ammeter c Ohmmeter d Potentiometer A volt meter is used to measure the potential voltage difference G 24 b 107 To read the amperage draw from an alternating electrical device a Set the meter to read voltage and place the two test leads on both sides of the load b Set the meter to read amperage and clamp the meter around both conductors feeding power to the device c Set the m
90. o charge larger systems in Page 75 of 120 Rev 1 1 4 22 07 the liquid state the technician must be certain that liquid is not allowed to enter into the compressor itself to prevent compressor damage C 12 i 50 What is the superheat of an R 22 air conditioning system if the evaporator boiling point temperature is 40 degrees f and the suction line temperature is 52 degrees f a 12 degrees f21 13 b 30 degrees f c 62 degrees f d 92 degrees f Equation Super Heat Suction line temperature evaporator pressure converted to temperature 52 40 12 degrees super heat C 12 e 51 When installing a central air conditioning system the entire refrigerant charge is typically a Added by the technician b Shipped and held in the evaporator c Shipped and held in the condensing unit 38 11 d Recovered before evacuation Most modern central air conditioning systems are shipped pre charged The charge is held in the condenser of the condensing unit during shipment The technician needs to verify the appropriate charge after system start up C 12 f 52 Vacuum pump oil must be changed on a regular basis because it can become very contaminated with a CFC s b Moisture 8 8 c HCFC s d All of the above When correctly performed all CFC s or HCFC s are recovered by a system recovery It is moisture that is attracted to the vacuum pump oil during evacuation C 12 g 53 To calibrate a gauge manifold a technician should a Open the gau
91. o rise from 250 microns to 500 microns before leveling off a Oil still in the condenser b An overcharge of refrigerant c An undercharge of refrigerant d Excessive contamination CRACT p 196 Oil remaining in the system will not have an effect on the micron reading an over charge or an undercharge also would have no effect after a proper recovery procedure When a system is excessively contaminated contaminants often cause an increase in micron gauge readings as these contaminants continue to vaporize E 18 d 78 To clean an excessively moisture contaminated system a technician may performa a Deep vacuum b Triple evacuation CRACT p 197 c Recovery d System recharge System recovery and system recharge play no role in removing the system contaminants Only by system evacuation can moisture be removed and on excessively contaminated systems a triple evacuation is sometimes necessary E 19 Evaluating the Metering Device UA HVACR Training Manual UAHTM unit 24 E 19 a 79 A full or partial restriction of the capillary tube is often the result of a Too much oil charge b Incorrect oil viscosity c Liquid refrigerant entering the compressor crankcase d All of the above UAHTM 24 29 A small amount of oil is always compressed and forced through the system However too much oil charge oil with too high of viscosity or liquid flooding of the compressor forcing excessive oil out of the compressor and into the system can cause full or parti
92. ooting gas heating problems furnace fails to operate at all inoperative blower the gas valve ignition problems Service call 1 shorted gas valve coil Service call 2 defective fan switch Set gas pressure on an LP or gas fired furnace Cut and ream steel pipe Manually thread steel pipe Install steel fittings on threaded steel pipe Reference United Association HVACR Training Manual Task 32 Install and service oil furnaces The oil furnace Fuel oil Combustion Testing combustion Combustion chargers and heat Exchangers Oil delivery to the unit oil storage tanks oil lines oil filters oil de aerators The oil burner motor fan fuel pump nozzle assembly igniter transformer Page 20 of 120 Rev 1 1 4 22 07 primary controls nozzles draft and venting power and direct venting sizing and installing the flue pipe Troubleshooting the oil burner air distribution system fuel and fuel tank oil piping oil burner combustion system controls Service call 1 No heat Service call 2 No heat Reference United Association HVACR Training Manual Task 33 36 Install and service hydronic heat Theory of hydronic heating systems the heat source aquastat reset low water cutoff expansion tank centrifugal pumps air vents and air separators press reducing valve pressure relief valve zone valves flow control valve balancing
93. or on when the room ambient decrease c To cycle the compressor off if the system runs low on charge ERHAC 14 5 d To cycle the compressor off if the system is over charged The room thermostat is used to cycle the compressor and the low pressure control is used as a Safety device which will open if the systems low side pressure drops to the cut out point usually about 2 5 psig H 28 c 138 A roof top air conditioning system with a defective condenser fan motor would be protected by A low pressure safety cut out switch A high pressure safety cut out switch ERHAC 14 5 Fan cycling pressure switch A temperature delay switch A high pressure safety cut out switch is used to shut the system down if a maximum head pressure is obtained A low pressure Page 99 of 120 Rev 1 1 4 22 07 aoe H 28 e switch is used to open the circuit if a minimum low pressure is met Fan cycling controls energize the condenser fan motors by high side pressure sensing this is commonly used where low ambient conditions are likely 139 A roof top air conditioner operating with a pressure type fan control maintains a minimum head pressure H 28 f a During low ambient conditions UAHTM 25 21 b During high ambient conditions c During high temperature conditions d During high pressure conditions Typically called a fan cycling control this pressure switch closes on pressure rise in the normal condensing pressure range and then opens on the fal
94. p B 8 e 36 If you find a person who is suffering from an electrical shock and has no pulse you should a Call for help b Begin CPR immediately 4 2 c Drag the person to safety d Turn off the building s power supply As soon as it is established the victim has no pulse CPR should begin immediately B 8 a 37 When treating frost bite you should a Gently rub the affected area b Run warm water over the affected area www chp edu besafe adults 02frostbite php base hs c Quickly warm the affected area with a heater or blow drier d Quickly put on butyl lined gloves To treat frost bite you should run warm water over the affected area as soon as possible Do not rub the area and do not apply any intense or direct heat Butyl lined gloves should be used before working materials of very low temperatures B 9 Agencies http www osha gov http www ansi org Page 72 of 120 Rev 1 1 4 22 07 B 9 a 38 Which agency concerns itself with the health and safety of America s work force a Air Conditioning Refrigeration Institute b American National Standards Institute c Occupational Safety amp Health Administration www osha gov d All of the above OSHA is the governing body of occupational health and safety concerns B 9 c 39 Which organization coordinates the development and use of voluntary consensus standards in the United States and represents the needs and views of US Stakeholders in standardization forums around the world
95. platforms must be rated at 5 times the intended load Page 120 of 120 Rev 1 1 4 22 07
96. r A single phase 120 240 volt electric service is made up of A L1 L2 and Neutral B L1 and Neutral C L1 L2 and L3 D L1 L2 L3 and a ground refers to the number of currents alternating at different time intervals in the circuit A amperage B resistance C phase D sine wave In the United States 3 phase power operates at A 60Hz B 120 Hz C 180 Hz D 240 Hz On a 240 volt circuit L1 and L2 cycle 60 degrees apart 120 degrees apart 180 degrees apart 240 degrees apart COM gt Page 48 of 120 Rev 1 1 4 22 07 125 126 127 128 129 130 131 Most commercial building s electrical service is A 120 volt single phase B 120 240 volt 3 phase C 240 440 volt single phase D 440 volt 3 phase A 3 phase Wye configuration supply voltage measures 208 volts between each leg What is the measured voltage from each leg to ground A 60 volts B 104 volts C 120 volts D 208 volts Because most induction motors require additional starting torque are implemented A start and run capacitor B start windings C shaded pole circuits D three phase winding Shaded pole motors can most easily be identified by A a heavy copper band B a start capacitor C arun capacitor D both start and run capacitor The primary application for shaded pole motors would be A when low start torque is required B when low run torque is required C when three phase power is not available D bot
97. r supply length of the refrigerant lines serviceability indoor unit configuration ease of condensate removal noise level return air location of the space to be conditioned Air distribution system duct system configuration duct system materials combination duct systems insulating and wrapping duct systems sealing duct systems Install galvanized metal duct systems Install flexible duct systems Install fiberglass duct systems Install round sheet metal duct systems Reference United Association HVACR Training Manual Unit 37 Task 11 System Connections Piping materials fittings copper pipe plastic pipe Installation supporting and insulating refrigerant lines length of the piping run choices of pipe fittings solder and solder joints refrigerant traps Installing supporting and insulating condensate drain lines drain line size drain line materials pitching the line Page 11 of 120 Rev 1 1 4 22 07 traps drain line terminations auxiliary drain pans safety float switches System wiring line voltage power circuit wiring low voltage control wiring Leak checking the system pressurizing the system marking the gauge Use tubing cutters Swag soft drawn copper tubing Flare soft drawn copper tubing Solder Braze Join plastic pipe Reference United Association HVACR Training Manual Unit 7 Task 12 System Evacuation Efficiency St
98. rating b When the humidistat signals for an increase of humidity c When the system control is set for cooling d Botha and b 34 9 A humidifier typically should only operate during the heating season when outdoor humidity levels are low The air handler blower must be operating and the system humidistat must be closed for the humidifier to operate Page 79 of 120 Rev 1 1 4 22 07 D 15 a 65 What is the maximum hardness of the water allowable for atomizing type humidifiers a 1 3 grains b 8 10 grains 34 9 c 20 30 grains d Up to 50 grains The maximum allowable hardness of water for atomizing humidifiers is 8 10 grains More than that will cause damage to the humidifier and a decreased amount of treated air D 16 Installing and Troubleshooting Air Quality Devices UA HVACR Training Manual UAHTM unit 34 D 16 a 66 High quality energy recovery ventilators a Use high volume blowers to exhaust stale air b Use a heat exchanger to absorb heat from the air being exhausted 34 6 c Use asmall heater to make up heat lost due to incoming fresh air d All of the above High quality energy recovery systems typically lower velocity blower and allow for a rather efficient heat exchange between incoming and outgoing air Typically these units do not mechanically heat or cool the incoming air D 16 b 67 To help prevent allergic reactions or upper respiratory problems humidifiers should be a Cleaned regularly b Treated with a
99. rcuit G 26 b a Amperage b Resistance c Phase EHRAC 7 1 d Sine wave Each phase L1 L2 and L3 is a current carrying conductor cycling at 120 180 degrees from the other phase s 123 In the United States 3 phase power operates at G 26 a 124 On G 26 b a 60 Hz EHRAC 7 1 b 120 Hz c 180 Hz d 240 Hz Standard power supply in the United States is delivered at 60Hz cycles a 240 volt circuit L1 and L2 cycle a 60 degrees apart b 120 degrees apart c 180 degrees apart EHRAC 7 1 d 240 degrees apart The difference in sine wave angle is 180 degrees on a 240 2 pole supply 125 Most commercial building s electrical service is G 26 b a 120 volt single phase b 120 240 volt 3 phase EHRAC 7 4 c 240 440 volt single phase d 440 volt 3 phase The service brought into most commercial buildings is 120 240 3 phase L1 L2 and L3 from this 3 phase service 240 volt single phase and 120 volt single phase can be obtained 126 A 3 phase Wye configuration supply voltage measures 208 volts between each leg What is the measured voltage from each leg to ground a 60 volts b 104 volts c 120 volts EHRAC 7 6 fig 7 15 d 208 volts On a 3 phase Wye connection any leg to ground would measure 120 volts Page 96 of 120 Rev 1 1 4 22 07 H CONTROLS H 27 Controls Electric motors and starting components HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and A
100. rd is used It does not need to be installed at the breaker panel nor is limited to a specific amperage circuit Page 69 of 120 Rev 1 1 4 22 07 B 6 Fire Safety www hanford gov fire safety extingrs htm fetypes B 6 a 29 If you encounter a fire with a source of flammable liquids a You must use a class A fire extinguisher b You must use a class B fire extinguisher www hanford gov fire safety extingrs htm fetypes c You must use a class C fire extinguisher d You must use a class D fire extinguisher Fire extinguishers are designed for use on a specific source of fires B 6 b 30 Multi purpose fire extinguishers rated A B C can be used on Flammable liquids Ordinary combustibles Electrical equipment All of the above www hanford gov fire safety extingrs htm fetypes Multi purpose fire extinguishers may be used on flammable liquids ordinary combustibles and electrical equipment type fires apop B 6 c 31 When using a fire extinguisher always aim a At the base of the fire www hanford gov fire safety extingrs htm fetypes b In front of the fire c At the top of the fire d All of the above Fire extinguishers when used should always be aimed at the base of the flame source Page 70 of 120 Rev 1 1 4 22 07 B 7 Tools equipment and material safety UA HVACR Training Manual UAHTM unit 4 B 7 e 32 A leaking refrigeration system not only can cause severe frost bite but can also cause a
101. rder to supply an adequate volume of refrigerant the system must also utilize a An accumulator b A receiver UAHTM 24 28 c An oil separator d A load controller Accumulators oil separators and load controllers are not necessary system components when a TXV is utilized A system receiver is necessary to hold the volume of refrigerant needed for times when the TXV throttles to the open position Page 84 of 120 Rev 1 1 4 22 07 E 20 Troubleshooting Steps and Service Calls E 20 b 84 An air conditioning system using a TXV with an undercharge of refrigerant can be identified by a Low suction pressure b Low system capacity c High superheat d All of the above UAHTM 29 11 All of these conditions would be obvious low charge would cause low suction pressure low capacity is normal with a low charge and low evaporator pressure and high return suction temperature equates to high superheat E 20 b 85 If an air conditioning compressor is allowed to operate with a low refrigerant charge the compressor is likely a To draw higher than normal amperage b To make excessive noise c To be very hot UAHTM 29 11 d All of the above With a low charge the amp draw would likely be lower than normal Unless there is also a loss of oil the compressor would actually operate more quietly A low refrigerant charge means high superheat and high superheat means high compressor temperature E 20 a 86 An air conditioning system using a TXV and operat
102. rine UAHTM 9 5 c Hydrogen d Carbon Most CFC refrigerants are made from the elements listed above However it is chlorine which is considered to be harmful to the ozone layer F 21 b 90 HCFC based blends are considered a Short term replacements UAHTM 9 10 b Long term replacements c Ozone friendly d Inefficient HCFC blends are considered short term replacements because although greatly reduced they still contain some chlorine F 21 c 91 Stratospheric ozone is considered good ozone because it filters out a Air pollution b UV b light rays UAHTM 9 2 c UV c light rays d CFC s Page 86 of 120 Rev 1 1 4 22 07 Ozone at ground level is toxic and very dangerous but ozone found in the stratosphere is considered good ozone as it filters out UV b rays from the sun F 21 d 92 HFC 134a refrigerant uses synthetic oil called a Polyol ester oil UAHTM 9 11 a Mineral oil b Paraffin oil c Polyalkalene ester oil Polyol Ester oil is used in modern compressors operating with HFC refrigerants Mineral oil was used in azeotrope refrigerant compressors Paraffin is a wax found in mineral oil Polyalkalene ester oil is a distracter F 21 e 93 ASHRAE s Standard 34 1992 refrigerant safety group chart classifies as the least toxic and not flammable a A3 b B3 c Al UAHTM f 9 10 d B1 The ASHREA standard 34 1992 classifies refrigerants in A column as low toxicity and B column as high toxicity The number
103. se from 250 microns to 500 microns before leveling off A oil still in the condenser B an overcharge of refrigerant C an undercharge of refrigerant D excessive contamination 78 To clean an excessively moisture contaminated system a technician may perform a A deep vacuum B triple evacuation C recovery D system recharge 79 A full or partial restriction of the capillary tube is often the result of A too much oil charge B incorrect oil viscosity C liquid refrigerant entering the compressor crankcase D all of the above 80 An air conditioning system with a fluctuating evaporator pressure would most likely be the result of a A defective circuit board B defective AEV C defective compressor D defective capillary tube 81 A system operating with a loose thermal expansion valve sensing element would cause the systems superheat to be A too low B too high C normal D erratic Page 40 of 120 Rev 1 1 4 22 07 82 Any evaporator with a pressure drop in excess of should use a thermal expansion valve with an external equalizer A 1 psig B 2 5 psig C 3 5 psig D 5 psig 83 Any system operating with a thermal expansion valve can automatically adjust to a change in the load condition In order to supply an adequate volume of refrigerant the system must also utilize A an accumulator B a receiver C an oil separator D a load controller 84 An air conditioning system using a TXV with an undercharge of refrigerant can be
104. so check the operation of H 29 b a Thermal over load b Current magnetic relay c Compressor contactor d Potential magnetic relay ERHAC 9 8 A capacitor start capacitor run motor uses a potential magnetic relay When a technician is making a diagnosis on this motor and finds a defective start and defective run capacitor the technician must also search for the cause of the defective capacitors which could have become defective because the potential magnetic relay failed to open after the system started 147 Most low voltage HVAC room thermostats can adjust temperature over shooting this adjustment would be a function of H 29 a a Fan cycle switch b Heat anticipator ERHAC 12 2 c Programmable timer circuit d Time delay relay The heat anticipator circuit in a low voltage room thermostat is designed to eliminate thermostat temperature overshoot When properly adjusted the heat anticipator opens the thermostat prior to the thermostat set point having been met The furnace blower would continue to operate removing the heat still in the heat exchanger and the thermostat set point would eventually be met 148 A current sensing lockout relay is an overload device that senses the current draw of the compressor through the H 29 b a Lockout loop ERHAC 17 5 b Thermo overload c Lockout timer d Condenser fan motor limit The Lockout loop consists of the current sensing lockout relay and any other control limit swit
105. supply voltage b High supply voltage c Shorted compressor and condenser motors d Defective condenser fan motor capacitor ERHAC 14 Practice service calls A shorted condenser fan motor capacitor could allow the fan motor to operate but it would operate at lower than normal RPMs After a short period of time the motor overload would open breaking the current path to the motor Within a short period of time with the fan motor not operating the compressor too would trip its overload H 29 d 154 Application Residential conditioned air system Type of Equipment Packaged air conditioner Complaint No cooling no indoor fan operation Symptoms 1 Line voltage available to unit 2 Closing of thermostat fan switch causes no action 3 Voltage at terminals C to R on unit low voltage terminal board is 0 volts Shorted run winding Open transformer circuit ERHAC 14 Practice service calls Shorted compressor run capacitor Defected room thermostat apop Page 104 of 120 Rev 1 1 4 22 07 The Transformer has no output voltage If line voltage is present at unit the transformer should also have power The transformer has an open winding l Heating l 30 Install and service electric heat I 30 b 155 The heating element found in electric forced air furnaces is typically made from a Silver b Chrome c Nichrome UAHTM 30 7 d Silver tungsten Resistive heating elements are typically made from Nichrome because of its durability and electri
106. t bite could be more intense and magnetism could draw metal jewelry to an electrical energy source the most important thing to know is that metal jewelry on the skin creates an excellent conductor making shocks or burns even more severe B 5 Electrical Safety UA HVACR Training Manual UAHTM unit 4 B 5 a 26 Whenever possible a technician should Lock out Tag out the electrical service panel before working on system to prevent B 5 c a The unit starting up automatically b Electrical shock c To prevent others from starting the system d All of the above 4 2 A B or C are all possible if the technician fails to Lock out Tag out 27 The third wire or ground wire is utilized to prevent B 5 d a Electrical shock from defective equipment 4 2 b The use of some extension cords c High voltage from reaching electrical tools d Counter EMF Most 2 wire extension cords will not receive a grounded electrical cord to prevent the appliance from shocking the user if the appliance is internally grounded Itis not for the purpose of inconvenience of the user or for use with other voltages Counter EMF is a distracter and does not apply to this question 28 A technician should never use an extension cord unless it has been plugged into a a GFCI 4 2 b Breaker panel c A circuit with at least 20 amps of service d All of the above The GFCI circuit should be used to interrupt the current flow any time an extension co
107. t system operating with a low voltage thermostat would have the heat relay wired in series with the A blower motor B electric heat element C thermostat heat anticipator D thermostat Y terminal Identify the safety found in electric duct heating systems A interlock B heat anticipator C transformer D high pressure switch Contactors and are commonly used to control the operation of the electric resistance heaters in electric furnaces A transformer B heat anticipator C high limit control D sequencer The U S Federal Trade Commission requires manufactures to provide an annual fuel utilization efficiency rating AFUE AFUE ratings are for the benefit of the consumer manufacture the technician the EPA DOWD Page 54 of 120 Rev 1 1 4 22 07 160 161 162 163 164 165 166 A high efficiency gas furnace utilizing hot surface ignition HIS will enter into lockout mode if ignition is not detected A 2 seconds or less B 4to 11 seconds C 15 to 20 seconds D 30 seconds High efficiency furnaces use plastic vent piping because A acidic flue gases B lower flue temperatures C condensation of flue gases D all of the above A technician uses which instrument to measure gas service and manifold pressure A anemometer B draft gauge C water manometer D manifold gauge When servicing the ignition transformer of an oil furnace correct secondary voltage would be A 120 vol
108. t the assistance of start components a Induction motor b Permanent split capacitor motor c Three phase motor ERHAC 9 9 d Shaded pole While all of these motors used in the proper application are reliable the 3 phase motor is the most rugged and reliable and it never requires the use of start components H 27 e 132 Identify the difference between a three pole contactor and a three pole magnetic starter a Acontactor has an overload circuit b A magnetic starter has an overload circuit ERHAC 11 3 c A magnetic starter has a solenoid coil d A contactor has solenoid coil In principal the contactor and the magnetic starter provide the same function except the magnetic starter also incorporates an overload circuit which opens each phase if an over current situation exists H 27 g 133 In identifying the common start run terminals of a split phase motor terminal A to B 10 ohms terminal A to C 3 ohms and terminal B to C 7 which terminalis common a Terminal A b Terminal B c Terminal C ERHAC 9 10 fig 9 40 d Ground terminal To identify the common terminal of a typical compressor measure the resistance across each pair A to B A to C and B to C when the pair with the highest resistance is located the remaining terminal is the common terminal H 27 f 134 Electronically commutated motors alter the output drive speed This is accomplished by altering a Electrical frequency UAHTM 17 24 b Electrical voltage c Electrical curr
109. tegory G Basic Electricity icceeraratahandnantaRGtavutatatanvatatigad 16 TaSk 23 Electical theo veces ese cece ees ee aed ea eee a A E tl AE R eae dio 16 Task 24 Measuring instruments ccceeeeeeeeeeeeeeeeneeeeeeeeeeeeeeeeecaeeeeeeeeeseeeneenaaees 16 Task 25 Electrical circuits Series and parallel ccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaeees 16 Task 26 Electric Service ests Ss es Sa i i de a Ai ts a A le MA eats Se 17 CALGOOMGI GONMOlStetsta tha tata tia taste tat ata theta tinea tie tala terial da tae lata a ts lata 17 Task 27 Electric motors and starting COMPONENTS ccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaeees 17 Task 28 Automatic Controls and devices ceeeeeeccecceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeenaaeees 18 Task 29 Electrical Troubleshooting ccccceceeeeeeeeeeeneeeeeeeeeeeeeeeeeneeeeeeeeeeseeeeeneaaees 18 categorii Meals nine Naa E A 19 Task 30 Install and service electric N at 2 eeeeeeeesceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeteaaeees 19 Task 31 Install and Service gas furnace o oo cece cece ceeeeee cette eeeeeeeeaeeeeeeeeeeeeeeeeenaaaees 19 Task 32 Install and service Oil fUNACES eee eee eeeeeeeeee cece eee eeeeeeeeeeeeeeeeeeeeeeeeeenaaeees 20 Task 33 36 Install and service hydronic heat ccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 21 Task 37 Install and service heat PUMPS cece ee eeeeeeee eee e eee eeeeeeeeeeeeeeeeeeeeeeeeee
110. ters Ammeters Ohmmeters Analog meters Digital meters Multimeters Megometer Micro amp meter Reference HVAC Light Commercial STC Version 1 11 06 Task 25 Electrical circuits series and parallel Wiring diagrams Wire size Circuit protection fuses circuit breakers GFCI Reference HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditioning Page 16 of 120 Rev 1 1 4 22 07 Task 26 Electric Service 120 240 V single phase service Three phase service Reference HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditioning Category H Controls Task 27 Electric motors and starting components Motor uses Motor power and starting torque Motor types Single phase motors shaded pole motors split phase motors capacitor start induction motors permanent split capacitor motors capacitor start capacitor run motors Three phase motors motor starters stator windings Wye configuration stator windings Delta configuration three phase motor starting Variable speed motors Procedures identifying the common start and run terminals on a split phase motor checking the coil and contacts on a DMR checking the coil and contacts on a PMR check capacitors Reference HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditioning Page 17 of 120 Rev 1 1 4 22 07
111. the above 39 Which organization coordinates the development and use of voluntary consensus standards in the United States and represents the needs and views of US Stakeholders in standardization forums around the world A Occupational Safety amp Health Administration B American National Standards Institute C Air Conditioning Contractors of America D none of the above Page 34 of 120 Rev 1 1 4 22 07 40 Identify the air distribution system used in modern residential buildings in which the air pressure remains steady from one end of the system to the other A radial duct system B reducing plenum system C perimeter loop system D flex duct 41 When installing galvanized rectangle duct 8 x 20 the metal should be at least A 16 gage B 24 gage C 28 gage D 32 gage 42 When the proper size duct materials are used the occupants of the home should A not feel air movement B should not hear air noise C should not feel temperature swing D all of the above 43 When conditioned air travels through an unconditioned space such as an attic or crawl space the duct must be insulated if the air temperature difference is A 5 degrees f B 10 degrees f C 15 degrees f D 20 degrees f 44 Air Conditioning Refrigeration ACR tubing is measured by its A inside dimension B outside dimension C nominal dimension D wall thickness 45 On air conditioning systems the tubing is often insulated to reduce heat transfer to the refr
112. ts B 600 volts C 6 000 volts D 10 000 Volts When servicing the oil burner that repeatedly locks out the technician tests the Cad Cell In the presence of light the correct OHM reading should be A 0 OMHS B 600 to 1000 OMHS C 50 000 to 100 000 OMHS D Infinity A standard oil burner nozzle identified as 80 degrees of angle and 1 00 GPH would deliver approximately how many BTUs per hour A 40 000 BTUs B 80 000 BTUs C 100 000 BTUs D 140 000 BTUs Centrifugal pumps used in hydronic heating are considered non positive displacement pumps because A they do not add significant pressure to the system B because they do add significant pressure to the system C because the pistons are very small D none of the above Page 55 of 120 Rev 1 1 4 22 07 167 168 169 170 171 172 A typical residential light commercial hydronic heating system the expansion tank A provides space for the heated water to expand B provides space when the water cools down C increases the water pressure so the water does not expand D maintains a constant water pressure equal to house pressure A residential hydronic heating system using three zone valve controls rated 24 Volt 50 amp each would require a control transformer rated at A 20VA B 30VA C 40VA D 60 VA When installing a hydronic heating system the use of slow opening closing zone valves allows for A the thermostat s heat anticipator to operate
113. use A the system always runs in the maximum heat position B the system always runs in the maximum cooling position C the system is always bringing in outside air D the system is always exhausting inside air When zoning a building for the purpose of climate control zones are generally divided into areas by A floors 1st floor 2nd floor B exposure north side south side etc C occupancy number of people type of activity D all of the above Page 60 of 120 Rev 1 1 4 22 07 201 202 203 204 205 When working on an upper floor or a roof top of a building the top of the ladder should extend above the top edge of the roof by at least A 1 foot B 3 feet C 5 feet D never use an extension ladder on a roof top When gas pipe is installed across a roof the pipe must be A fastened with galvanized joints B sealed with Teflon tape C supported and fastened D all of the above According to OSHA falls from are one of the leading causes of occupational fatalities and injuries A ladders B roof tops C windows D cranes OSHA recommends when climbing a ladder A keep your body out away from the ladder as far as possible B keep your feet as far to the outside of the rungs as possible C maintain a 3 point contact with the ladder at all times D all of the above Design specifications for Suspended Personnel Platforms require the support platform rating be at least the maximum
114. v 1 1 4 22 07 K 42 c K 42 f K 42 b 187 An optional arrangement added to a roof top air conditioning system which has a motorized damper and opens when the room thermostat calls for cooling and outdoor temperature and humidity conditions are met is called a An economizer ARI Chapter 17 p 798 b Heat recovery c Free ventilation d Desiccant cooling In geographic regions when moderate temperatures and low humidity is common during the cooling season an economizer package can significantly add to overall air conditioning efficiency 188 Roof top air conditioners typically are mounted on top of a roof curb 189 to help provide a leak proof connection to the roof The roof curb is generally high a 2 4 inches b 6 10 inches c 12 15 inches MRAC 24 20 d 24 30 inches The bottom of the roof curb is flashed into the building s roof to prevent rain and snow melt from penetrating into the building The Air conditioning unit is set on top of the curb above the normal snow line usually 12 to 15 inches Many roof top heating air conditioning systems are 2 stage heating or 2 stage cooling or both The primary purpose for this is a To allow a wider application of equipment b To allow for fluctuating loads ERHAC 12 3 c Less costly to build equipment d To use smaller gas lines and refrigerant lines With this type of equipment greater AFUE and SEER ratings can be achieved with smaller capacity systems such as
115. ve metering c Automatic expansion valve metering d All of the above UAHTMf 3 35 In small systems virtually any metering device could be found including these and more but primarily because of the difference in cost capillary tubes are used more widely A 2 b 15 The most common refrigerant used in existing modern residential or light commercial air conditioning systems is a R 12 b R 22 UAHTM 3 12 c R 134a d R410a Because of overall system efficiencies and operational purposes air conditioners using R 12 and R 134a were never widely marketed R 22 has been used almost exclusively since the early 1960 s In the past few years the development of R 410a Puron has changed everything and today most manufacturers are beginning to produce A C systems with this new environmentally friendly refrigerant Over the next several years R 410a will command the greater market share A 2 b 16 Refrigerant 410 has special characteristics including higher operating pressure a small temperature glide and is a An azeotrope b A near azeotrope UAHTM 3 12 c A zoetrope d ACFC Page 66 of 120 Rev 1 1 4 22 07 Technically R 410a is a zeotrope However because of its very low temperature glide it is identified as a near azeotrope An azeotrope is a combination of refrigerants that when mixed together combine chemically to create a new molecule A zeotrope is defined as a combination of refrigerants which when combined does not chem
116. y listed d All of the above UAHTM 9 16 Type classification includes appliances with 5 pounds or less of factory charge hermetically sealed and specifically listed as Type such as household refrigerators and freezers dehumidifiers window air conditioners packaged terminal air conditioners and under counter ice makers G Basic Electricity G 23Electrical Theory HVAC Light Commercial STC Version 1 11 06 Electricity for Heating Refrigeration and Air Conditioning G 23 a 99 If a DC power supply of 20 volts causes 2 amps of current to flow in a circuit a The resistance of the circuit is 10 ohms HVAC LC b The power consumed by the circuit is 100 watts c The power consumed by the circuit is 10 watts d The resistance of the circuit is 40 ohms Apply ohms law R E Page 88 of 120 Rev 1 1 4 22 07 G 23 b 100 A is often used as a graphic representation of alternating current a positive symbol b negative symbol c Sine wave EHRAC 7 1 d North pole or South pole The sine wave symbol shows the alternating current from its peak positive voltage to its peak negative voltage G 23 c 101 Which of the following is true regarding current flow in a parallel circuit a Current flow is equal through all branches of the circuit b The paths with higher resistance will have higher current flow c The paths with lower resistance will have higher current flow HVAC LC d As addition branches are added to the circuit the total curre

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