Home

690A-0999 M1 Series sm.p65

1. MaAYOS 35NVHO e 3 v E m z E m 5 z 07 asa ay Nauos _ n SIHO l A 7TOHINOO MOTT3A MOTI3A LINT XNV HOLIMS 3JO NO T nn HOLO3NNOO ejz i juejeAinbe 51 adh 1 2 601 esn peoejdaJ eq 15 y perjddns se sasim y jo Aue aaads 315NIS JO ees 0 eq 1 Buruoou SALON Figure 25 Gas Direct Ignition Furnace Heating amp A C Ready All M1M Models 35 35 Event 031873 5 0 4521877 eanou 1oe qns 8660 v069 6660 v069 66 60 v S ui peiuud UTEC M1 FURNACE CONTROL SEQUENCE Start Up Shut Down
2. Green or Bare Ground et ae Ground Field Supplied Disconnect Within Sight of Furnace Figure 6 Line Voltage Field Wiring 5 GAS SUPPLY CONVERSION AND LIGHTING M1G AND M1M MODELS GAS PIPING Sizing and installation of fuel lines must be in accordance with federal state and local regulations All piping shall be black iron pipe or equivalently sized steel tubing Internally tinned copper tubing may be used for gas supply systems Fuel line installations other than typical installations shown in Figure 7 must comply with the fuel piping provisions stated in the Federal Manufactured Home Standard H U D TITLE 24 PART 280 and the National Fuel Gas Code ANSI Z223 1 NFPA 54 a Optional fuel inlet lines are available for all gas furnace models to permit the addition of a 1 2 F P T shut off valve above the floor NOTE Shut off valve must be designed and listed for use with liquid petroleum LP gas The gas supply to your home will either be Natural Gas or LP bottle gas Your furnace is factory equipped to operate on Natural Gas If your gas supply is LP you must convert the furnace The necessary instructions for the gas conversion are found on the lighting instruction label attached to the furnace in Section 16 Service Guide For natural gas operation the furnace is designed for 7 W C inlet pressure Pressure is reduced to 3 1 2 W C by the pressure regulator in the gas
3. a The first lighting of the furnace after any home setup must be performed by a qualified service technician b If this appliance has a pilot that must be lit by hand follow these instructions exactly Figure 8 Convertible Pressure Regulator Cap BEFORE LIGHTING smell all around the furnace for gas Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor Robertshaw d WHAT TO DO IF YOU SMELL GAS Do not try to light Valve any appliance Do not touch any electric switch and do notuse any phone in your building Immediately call your gas supplier from a neighbor s phone Follow the gas suppliers instructions If you cannot reach your gas disp supplier call the fire department Configuration e Useonlyyourhandto pushinthe gas control lever Never use tools If the lever will not push in by hand don t try to repair it Call a qualified service technician Force or attempted repair may result in a fire or explosion f Donot use this furnace if any part has been under water Figure 9 Convertible Pressure Regulator Immediately call a qualified service technician to inspect the furnace and to replace any part of the gas valve or control system which has been under water FURNACE ORIFICE SIZE AND ALTITUDE FEET MODEL OUTPUT CAPACITY SEALEVEL 2000 3000 4000 5000 6000 7000 8000 9000 10000 ORIFICE SIZE NAT GAS 30 30 30 31 32 M1M G 056 ORIFICE SIZE LP 46 47 47 47 48 4
4. Transformer i Picture 3 Transformer On Off Switch Picture 4 This switch turns electrical power to the furnace on and off The switch must be set in the position for the furnace to operate For M1G models in warm weather there is a possibility of the blower coming on periodically or operating continuously due to a heat buildup within the furnace by a combination of warm weather and heat from the pilot This is normal operation as long as there is power to the furnace and the On Off switch is at the ON position If blower operation is not desired the On Off switch may be set in the OFF position to cut the electrical power to the furnace Picture 4 On Off Switch 17 Low Voltage Wiring Install the thermostat per the manufacturer s instructions The low voltage 24 vac connec tions from the thermostat are made at the terminal strip on the control board in the furnace See Figure 4 for the proper connections for heating only two wire and heating cooling four wire applications The recommended minimum wire gauge for thermostat wiring is shown in Table 4 The thermostat must not be installed on an outside wall or any other location where its operation may be adversely affected Adverse effects include radiant loading from fireplaces sun light or lighting fixtures and convective loading from warm air registers or electrical appliances To check the heat anticipator set
5. lt USE FAN clamo SWITCH TRANSFORMER BLOWER RELAY ORANGE GRAY BLACK MANUAL RESET VENT SWITCH GROUND SCREW BLUE FURNACE ELECTRICAL BOX M1G C D Heating replace orange wire with FIELD 115V red wire low speed FIELD 24V NOTE To run at same speed in both heating and cooling mode GAS VALVE remove wire from either terminal 4 or 6 on the relay then attach jumper to terminals 4 and 6 7038890 Figure 19 Gas Atmospheric Furnace A C Ready M1G B C D 056 070 Models 24 NOTES 1 Incoming power must be polarized Observe color coding See furnace data label for electrical information 2 If any of the original wires as supplied with the appliance must be replaced use 105 C Thermoplastic type wire or its equivalent ON OFF SWITCH SUPPLIED BY INSTALLER AUX LIMIT BLUE HOUSING CAP BLACK Lt NEUTRAL PRESSURE SWITCH FURNACE ELECTRICAL BOX BUSHING 3 GAS VALVE FAN ON AUTO FIELD 24V SWITCH 7038880 Figure 20 Standing Pilot with Induced Draft Furnace M1GH 077 090 Models HEATING COOLING NOTES AUX LIMIT 1 Incoming power must be polarized Observe color coding See furnace data label for electrical information 2 If any of the original wire
6. Ice forms around air inlet and blocks off combustion air Install all weather cap 903656 4 Conditions are such that pilot will not stay lit All the above have been tried with no resolution Install optional HSI conversion kit 903428 23 NOTES 1 Incoming power must be polarized Observe color coding See furnace data label for electrical information Kr A AUX LIMIT 2 If any of the original wires as supplied with B ALL BLUE the appliance must be replaced use 105 C Thermoplastic type wire or its equivalent A ui MMON FOR OPTIONAL ON OFF CONNECTOR Nor lt HOUSING ACCESSORY KITS SUPPLIED BY INSTALLER ORANGE L1 NEUTRAL ua MANUAL RESET GROUND VENT SWITCH SCREW FURNACE ELECTRICAL BOX GAS VALVE FIELD 115V FIELD 24V 7038870 Figure 18 Gas Atmospheric Furnace M1GH 056 070 Models NOTES HEATING 1 Incoming power must be polarized Observe color COOLING coding See furnace data label for electrical AUX LIMIT information BLUE 2 If any of the original wires as supplied with the appliance must be replaced use 105 C Thermoplastic type wire or its equivalent BLUE WHITE ON OFF CONNECTOR SWITCH HEATING COOLING fea 8 2
7. 8 Hot Surface Ignition System Model M1M SEQUENCE OF OPERATION M1M SERIES Call for heat the thermostat calls for heat by energizing the W terminal The control checks to see the pressure switch is open If the pressure switch is closed when the call for heat occurs the control will begin to flash 3 on the Status LED after 10 seconds and wait indefinitely for the pressure switch to open Pressure switch proving the control energizes the induced draft motor and waits for the pressure switch to close If the pressure switch does not close within 10 seconds of the inducer energizing the control will begin to flash 2 on the Status LED and wait indefinitely for the pressure switch to close Pre purge the control runs the inducer for a 45 second pre purge time HSI warm up the control energizes the HSI for 30 seconds The inducer remains energized Ignition activation period the control energizes the main gas valve for 6 seconds The inducer and HSI remain energized Flame proving the control de energizes the hot surface ignitor The gas valve and inducer remain energized If flame is present 1 second after HSI de energizes the control goes to blower on delay If a flame is not present the control de energizes the gas valve and proceeds with ignition retries as specified below Blower on delay If flame is present the control energizes the blower on HEAT speed 30 seconds after the gas valve opened 24 seconds from H
8. Before installing an air conditioner system consult home manufacturer for duct system maximum capacity Location size and number of registers should be selected on the basis of best air distribution and floor plan of the home CAUTION HAZARD OF ASPHYXIATION Do not cover or restrict return air opening 3 VENTING AND COMBUSTION AIR ROOF JACK SELECTION Note Install only Roof Jack Assemblies listed in Table 3 on this heating appliance a Determine depth of ceiling cavity from center of roof opening to center of ceiling opening See Dimension A in Figure 1 b Determine ceiling height and subtract height of furnace See Dimension B in Figure 1 c Add dimensions A B and X from Table 3 and Figure 2 if slant deck flashing is used The total length of A B X must be within the minimum and maximum range of one of the Roof Jacks listed in Table 3 ROOF JACK TROUBLE SHOOTING The roof jack assembly is a telescoping type assembly see selection thatis made up of a pipe within a pipe construction The inner pipe 5 is for the flue gases to exit the home The outer pipe 8 is using the space in between the 5 and 8 pipe for combustion air Ifthe furnace is smothering itself out after a short time on natural draft models or pressure switch does not make contact on M1M model slide up air inlet a few inches and check for debris in pipe Clean out and check complete flue assembly for bloc
9. Yes Retry lt will retry 4 more times ue Burners stay on Every Soft lock out blinks 4 times longer than 6 seconds Hour on status light Yes Power down and back up to reset Ignitor turns off 7 seconds after gas valve opens Yes Main blower starts after delay time 30 seconds Yes NO Check for voltage No__ Circuit board 3 blinks at inducer molex plug Replace Inducer Blower Replace NO Pressure switch Board stuck closed N 20 Circuit board blinks 2 times Replace Yes pressure switch No a Pressure switch Is there gt 8mA on W terminal open of circuit board Replace t stat or add isolation relay Yes No Greater than Check venting 30 W C differential at pressure switch Yes Replace pressure switch No Check for voltage Box Replace circuit board at molex plug Yes Replace ignitor No 24volts at gas valve Insure lever is in ON position Insure gas inlet pressure is below 14 W C Yes Replace gas valve No Manifold Gas No Pressure Available Check and adjust ignitor Yes gap to 5 16 Flame light on Yes Replace board Flame light blinks at 1 uA weak signal No Replace circuit board No Check for voltage at No com and heat terminals Eur Yes Flame inducer main blower stay on until call for heat ends Inducer post purges for 30 seconds Main Blower Fan Off Timing Check motor and capacitor 27
10. are the primary causes of ignitor failure Figure 24 M1M Burner Assembly Burner Assembly In order to perform procedures such as inspecting for presence of LP gas in chamber cleaning burner and inspecting the heat exchanger the burner assem bly must be removed Changing Complete Burner Assembly 1 Gas Line Remove the furnace door then disconnect and remove the gas line from the valve body by using two backup wrenches Be careful not to damage the pipe threads or introduce dirt into the gas line 2 Wiring Leads Remove the two low voltage wiring leads from the valve body by carefully pulling them off the connectors Be careful notto damage or dirty the connector ends 3 Burner Mounting Plate Using a philips remove the screws that hold the main burner mounting plate to the furnace 4 BurnerAssembly Slide the burner assembly out from the furnace 5 Reverse procedure to reinstall NOTE Be sure to install the gasket Gas Valve The gas valves for the gas furnaces are a 100 shut off type and will fail safe if for some reason the gas is turned off When the thermostat calls for heat the first and second valves open by the energization of two solenoids If 24 vac is available at valve and no gas flows valve is defective NOTE Be sure gas pressure is available at the inlet to the valve and does not exceed 14 w c 1 2 lb If this condition exists valve will lock down and no gas will flow
11. closes on temperature rise andisin series with the heating speed of the air circulating blower Upon a call for heat and when the burner builds up a supply of heat the fan switch wraps closed at 115 5 and blower motor starts After the thermostat opens and the chamber cools down the fan switch opens at 95 5 and blower shuts off If blower does not start after warm up check blower for power If blower has power see Blower Checkout section If blower does not have power check for line voltage across the fan switch If voltage is present the switch is open You also can remove wires and ohm out after warm up NOTE Use tape to make sure wires do not touch anything An infinity reading indicates the switch is open If blower motor does not shut off and chamber has cooled and fan switch is off check across fan switch contacts If there is no voltage pull the single orange wire off take care not to touch uninstalled terminal or lay wire against metal If blower shuts off fan switch is stuck closed If switch does not close or open properly it will have to be replaced Turn off power remove wires and remove the two phillips screws to remove switch Install new switch and re test Blower Assembly Picture 10 If the blower motor has power to it heating speed and neutral and motor does not start motor has electrically opened up NOTE Some models incorporate a capacitor this should be checked first To replace m
12. control may contribute to blower short cycling Nordyne does not consider this to be a warranty issue Optional Add On Air Conditioning Packaged Units Necessary when the Furnace is Used with Some Central Air Conditioners f an air conditioner is installed that does not use the furnace blower for air distribution and that operates independently of the furnace the thermostat system must have an interlock to prevent the furnace and air conditioner from operating atthe same time This interlock system usually contains either a Heat Cool switch which must be turned to the Heat or Cool position to activate either heating or cooling operation or a positive OFF switch on the cooling thermostat The furnace mustalso be equipped with an automatic damper See Figure 37 or 38 NORDYNE p n 901996 for furnaces without coil cavity or p n 901083 with coil cavity to prevent coldairfrom being discharged up around the heat exchanger Cold air may cause condensation inside the heat exchanger which can lead to rust and early failure Optional Add On Air Conditioning Split Systems There is aNORDYNE split system or package air conditioner designed for your total comfort needs Whether split system or single package an energy saving NORDYNE unitis avail able that has been designed specifically for manufactured housing applications and can best handle your home comfort needs Listed and ARI Certified all models are protected by t
13. power source and combustion blower relay contacts See wiring diagram e Picture 15 Combustion Air Blower HH J Orifice Ring Silicone sper di PS Picture 17 Blower OHM Picture 18 Blower Open Motor 31 Combustion motor assembly replacement Using the information from above you have determined the combustion motor assembly needs to be replaced follow the outlined procedures 1 Disconnect Molex plug 2 Remove screws from the top and break silicone loose from orifice ring on top side of ventor assembly Figure Picture 26 inlet pipe may also break loose this is normal 3 Remove screws from bottom of assembly and remove the whole assembly 4 Mountnewassembly reattach screws to bottom remove from step 3 5 Re silicone orifice ring and combustion air pipe and reinstall screws to top removed in step 2 6 Reconnect Molex plug from step 1 and test Pressure Switch Picture 19 All M1M furnaces use a differential type pressure switch The purpose of this switch is to insure that a good supply of combustion air is supplied to the burner The combustion blower creates a differential innegative pressure lessthan atmospheric pressure across the orifice ring The switch is normally open and closes on a drop in pressure read in negative inches of water column Picture 19 Pres
14. senses the gas valve output as energized when it should be de energized and flame is not present the control shuts off all control outputs including the inducer motor to force the pressure switch to open If gas valve remains sensed as energized 15 seconds after the inducer shut off the inducer is re energized to attempt to vent the uncontrollable gas If the control senses the gas valve output as energized when it should be de energized and flame is present the control keeps the inducer motor and indoor blower motor energized until flame is removed Ifthe control does not sense that the gas valve is energized when it should be the control locks out with the Status LED flashing rapidly Combustion Air Blower All M1M models use a combustion air blower incorporated in series with the air inlet pipe Its purpose is to supply a forced draft method of combustion air The quality of air is determined by the inlet orifice ring located on the inlet to the motor assembly Upon a call for heat under normal conditions the combustion blower starts up and supplies combustion air to the chamber If motor does not start check to be sure call for heat is established and fault light is on solid See troubleshooting flow chart and sequence of operation for further details Then disconnect blower molex plug and check for voltage at plug If voltage is available and motor does not start replace motor If power is not available check back through
15. the furnace door In the event of any flashback or explosion immediately shut off the furnace and call your service technician Gas Control Lever Pilot Adjustment Figure 10 Standing Pilot Valve 12 TO TURN OFF GAS TO APPLIANCE a Set the thermostat to the lowest setting b Turn off all electric power to the appliance at breaker or fuse box before servicing c Remove the furnace door d Pushinthe gas control lever slightly and move to the left to OFF DO NOT FORCE e Replace the furnace door CAUTION Do not use matches lighters candles or other sources of open flame to check for gas leaks Leak Check Afterthe gas piping to the furnace is complete all connections must be tested for gas leaks To check for leaks use only a soap and water solution or other approved method NOTE When pressure testing gas supply lines at pres sures greater than 1 2 psig 14 in water column the furnace must be disconnected from the gas supply pip ing system to prevent damage to the gas control valve If the test pressure is less than or equal to 1 2 psig 14 in water column the furnace must be isolated from the gas supply line by closing off the main shut off valve Pilot Bracket Figure 11 Lighting Furnace 6 ACCESSORIES Relay Boxes Only the M1GH requires a relay box All other M1G and M1M furnaces are AC ready The M1GH series furnaces are certified
16. this causes a greater negative atthe inlet side connection This will actto open switch To prove this disconnectthe hose going to the top connection If switch closes there is too much negative pressure being created on the inlet side Look for air inlet restriction Lower Lesser Differential Negative Pressure Than Closing Pressure Insufficient negative pressure measured at the combustion blower may be caused by 1 Restriction on outlet side of combustion blower blocked flue or debris building up in flue Leak lack of restriction on inlet side Inducer inlet leaking inducer blower props loose or wrong restrictor orifice To test for restriction in outlet pipe exhaust to verify problem is outside of furnace disconnect exhaust for test period only and start furnace If furnace starts look for problem in vent pipe Reconnect after testing Higher than normal negative pressure at top connection acts to open switch may be caused by 1 Restricted combustion air inlet pipe 2 To verify if problem is in inlet pipe disconnect pressure switch hose at top connection and start furnace If furnace starts look for problems men tioned above in inlet pipe Note top connection acts to open contacts on differential switch NOTE Inlet Pressure Outlet Pressure Differential Pressure Table 9 Lower lesser Differential Negative Pressure Than Closing Pressure 32 2 1 aheat exchanger restriction o
17. through it Step Flow during the dwell time there is no flow through the main valve since itis closed A calibrated bypass hole provides step flow for soft ignition and draft build up during the dwell time The bypass flow can be custom tailored from 40 to 70 33 of full flow butis also notfield adjustable Atthe end of the dwell time the main valve opens allowing full gas flow Testing Operating Pressure a Remove furnace door and set the gas valve in the OFF position b Using a3 16 Allen wrench remove the plug from the right side of the valve c Install the barbed adapter in the plug hole Tighten by hand at first then with an open end wrench Do not overtighten d Install the hose and manometer to the barbed fitting Be sure to check all connections for leaks e Set the gas valve switch to the ON position With the valve in the ON position set the thermostat above roomtemperature so the furnace will run throughout the test procedure g With the furnace operating check for valve staging The operating pressure should be 3 5 WC for Natural Gas 10 WC for LP gas Blower Assembly the blower motor has power to it heating speed and neutral and motor does not start motor has electrically opened up NOTE Some models incorporate a capacitor this should be checked first To replace motor Remove wires going to motor Remove single Phillips screw in upper left corner Raise entire b
18. wire gauge for thermostat wiring is shown in Table 5 The thermostat must not be installed on an outside wall or any other location where its operation may be adversely affected Adverse effects include radiant loading from fireplaces sun light or lighting fixtures and convective loading from warm air registers or electrical appliances To check the heat anticipator setting Jump out R to W at thermostat with 10 Loop Helex and measure current draw after blower starts Divide by 10 Example 4 Amps 4 set at 4 Limit Control Picture 14 This furnace is protected by two high temperature safety limit switches The auxiliary upper limit switch and the high temperature lower limit switch are automatic reset types If either limit trips the burner will shut off and status light will flash 1 M1M Control Board Replacement Replace the control board only after determining a failure has occurred in it Most problems that are blamed on control are actually external to control See troubleshooting section If control has failed use the following procedure to replace 1 Disconnect power to unit by turning off power switch Disconnect molex plugs and all push on terminal connections Note connections for rehook up 3 After all wire connections have been removed you must squeeze the four white stand offs to remove board See Pictures 18 showing board removed with exposed standoffs remaining 4 Carefully line up holes
19. 0 x x 3 4 x 5 X x 3 x 4 x x 5 X x 3 x 4 x 5 X X X X X X X X X X X X X X X Thermostat Circuit 24 Volts 60Hz 30 VAC Norm Anticipator Setting 0 4 Manifold Pressure Natural Gas 3 5 w c Nominal blower capacity only LP Gas 10 w c relay must be field added For Canadian High Altitude 2 000 4 500 reduce the gas manifold pressure to 3 0 w c for natural gas and to 8 w c for LP gas Table 1 M1 Furnace Specifications a Federal Manufactured Home Constructions amp Safety Regardless ofthe location the return air opening into the Standard H U D Title 24 Part 3280 707 a 2 closet shall not be less than specified in the appliance s b American National Standard ANSI 119 2 NFPA 501C listing for all recreational vehicle installations b Means shall be provided to prevent inadvertent closure c American National Standard ANSI Z223 1 NFPA 54 by a flat object placed over the return air opening when it and or CAN CGA B149 for all gas fired furnace models is located in the floor of the closet versus the vertical front d American National Standard ANSI Z95 1 NFPA 31 or side wall or CSA B139 for all oil fired furnace models c Thecross sectional area of the return duct system lead e American National Standard ANSI C 1 NFPA 70 and or ing into the closet when located in the floor or ceiling shall CSA 22 1 Canadian Electric Code Part 1 for all ele
20. 8 49 49 50 OUTPUT MBTUH 45 4 41 8 40 1 38 5 37 0 35 5 34 1 32 7 31 4 302 ORIFICE SIZE NAT GAS 24 25 26 27 27 28 28 29 29 30 M1M G 070 ORIFICE SIZE LP 43 43 44 OUTPUT MBTUH ORIFICE SIZE NAT GAS 21 23 23 24 25 26 27 28 28 29 M1M 077 ORIFICE SIZE LP 40 41 42 42 42 43 43 44 44 45 OUTPUT MBTUH 61 7 56 9 54 6 524 50 3 483 46 4 44 5 42 7 41 0 ORIFICE SIZE NAT GAS 21 23 23 24 25 26 27 28 28 29 M1G 077 ORIFICE SIZE LP 40 41 42 42 42 43 43 44 44 45 OUTPUT MBTUH 59 9 55 2 53 0 50 9 48 9 46 9 45 0 43 2 41 5 39 8 ORIFICE SIZE NAT GAS 19 20 21 22 23 24 26 MiM 090 ORIFICE SIZE LP 38 39 40 41 41 42 43 OUTPUT MBTUH 71 7 66 1 63 5 60 9 58 5 56 1 53 9 51 7 49 7 47 7 ORIFICE SIZE NAT GAS 17 18 19 19 20 21 22 23 24 26 M1G 090 ORIFICE SIZE LP 38 39 40 OUTPUT MBTUH Reference Sources ANSI Z233 1 amp NFPA 54 National Fuel Gas Code For Canadian high altitude 2 000 4 500 reduce gas manifold pressure to 3 0 W C for natural gas and 9 W C for LP gas NOTE Do not attempt to change the size of an orifice by drilling it out To do so will void the manufacturer s warranty Table 7 High Altitude Derate 11 LIGHTING INSTRUCTIONS FOR STANDING PILOT MODELS Stop Read the safety information Set the thermostat to the lowest setting Turn off all electric power to the appliance Push in the gas control lever sligh
21. ACCESSORIES Relay boxes 13 Cooling amp aini 13 Furnace accessories for package unit add 13 timer aiia 13 All Weather Cap 13 SEQUENCE OF OPERATION COMPONENT PARTS AND TROUBLESHOOTING M1G STANDING PILOT MODEL M1G Troubleshooting flow chart M1G 056 070 15 Troubleshooting flow chart M1G 077 090 16 Sequence of operation heating 17 TROUBLESHOOTING Power supply imet eder tti 17 Transformer 17 On off switch and fan switch 17 Low voltage wiring eene 18 Limit controls iiia co te eec tici Ens 18 Combustion air relay 077 and 90 only 18 Combustion air blower 077 and 90 only 18 Pressure switch 077 and 90 only 18 Burner assembly tiene ceniza 19 Gas valve 20 Pilot assembly Thermocouple and Venturi 20 ne rc sre 21 Blower assembly 21 Heat 22 22 Pilot Outage Chart sse 23 WIRING DIAGR
22. AMS M1G Natural Draft AC adaptable 24 M1G Natural Draft AC ready 24 M1G Forced Draft AC adaptable 25 M1G Forced Draft AC ready 25 HOT SURFACE IGNITION SYSTEM MODEL M1M Troubleshooting flow chart 27 Sequence of operation heating 28 TROUBLESHOOTING Power supply totes ti 28 Transformer 28 Low voltage 29 Limit controls sestiana nnsa 29 Intergrated control board 29 Combustion air blower 31 Pressure 32 Hot surface ignitor 33 Burner assembly 33 Gas Vale 33 Blower assembly eia 34 Heat 34 WIRING DIAGRAM INTRODUCTION This service manualis designed to be used in conjunction with the installation manual provided with each furnace The downflow sealed combustion furnaces illustrated in this service manual representthe very latest in high efficiency gas furnace technology Certain controls within the furnace consist of highly sophisticated electronic components which are not user serviceable I
23. Air Pipe Furnace SEC ONERE Y ELECTRICAL WIRING Line Voltage Wiring See Figure 15 The line voltage 115 volt to the furnace must be supplied from a dedicated circuit containing the correct fuse or circuit breaker for the furnace See Table 5 An electrical switch should be readily accessible from and within sight of the furnace All line voltage connections must be made within the junction box located within the furnace The furnace cabinet must have an uninterrupted unbroken ground to minimize injury should an electrical fault condition occur The controls used in this furnace also require an earth groundto cooperate properly Acceptable methods for ground ingare electrical wire or conduit approved for electrical ground service Do not use gas piping as an electrical ground NOTE Proper line voltage polarity must be maintained in order for the control system to operate correctly Verify that the incoming neutral line is connected to the white wireandthe incoming hot lineis connectedtothe black wire in the furnace junction box This furnace will not operate unless polarity and ground are properly con nected See Figure 16 Never use gas lines as ground To determine polarity the incoming power supply should be checked The Hot lead will read 115V to ground The neutral should read OV to ground ROOF JACK SLANT DECK PITCHED FLASHING ROOF X SEE TABLE 6 CEIL
24. ING CAVITY A CEILING ROOF OPENING CEILING OPENING Figure 2 ROOF JACK WITH 2 12 12 SLANT FLASHING 21 12 SLANT DECK 5 12 ROOF SLOPE Figure 1 Roof Jack Assemblies Figure 3 MiG A C Supply Voltage Thermostat Ready Furnace Supply voltage to the furnace should be nominal 115 volts It Red Red boos must be between 103 volts and 127 volts Supply voltage to the Re furnace shouldbe checked with furnace in operation and blower running Voltage readings outside the specified range can be 1 expected to cause operating problems Their cause MUST be White AN White investigated and corrected G Green In Green 1 CONNECT THERMOSTAT WIRES Y NEN Grey a Insert 24 volt wires through the plastic grommet just m above the control panel w Wy b Connect the thermostat wires to the furnace low voltage pigtails see Figure 5 To Cooling Unit c Connect low voltage circuit to the wall thermostat d A hole may be made in the furnace cabinet to ease Figure 4 Thermostat Wiring A C Ready Models thermostat wiring Make sure that the wiring is protected 4 a Thermostat Wires from the sharp edge of the added hole Furnace A Control Box NOTE The thermostat should be installed 4 to 5 feet above On Off the floor on an inside wall which is relatively free from direct sources of heat or cold drafts The nominal anticip
25. M1 Series M1G and M1M Furnaces Service Manual Typical meters used to service M1 furnaces A Differential Pressure Gauge B Volt Ohm Meter C Manometer D Inclined Manometer TABLE OF CONTENTS INTRODUCTION Model Identification Code 4 Serial Number Identification 4 Clearances and HUD Requirements 5 Unit 5 CIRCULATING AIR SUPPLY Return air requirements 6 Blower performance 6 Supply air systems 7 VENTING AND COMBUSTION AIR Roofjack selection eene 7 Roofjack troubleshooting 7 Application of high wind and arctic caps 8 ELECTRICAL WIRING Line voltage iecit cerco deron 8 Low voltage 9 GAS SUPPLY CONVERSION AND LIGHTING M1G M1M MODELS Gas PIPING uoc aed da eere na aes eu das 10 Gas conversion nat to 10 Gas safety nat and 11 Derating for high altitude 11 Proper pilot lighting M1G only 12 Leak checking gas line 12
26. Picture 12 on the new board over standoffs and push into place Caution push from outside edge only be careful of fragile components Reinstall all molex plugs and wires removed in step 2 Apply power and re test Stand off Holes Picture 12 UTEC Ignition Control Stand offs di f S aT Picture 13 Ignition Board Removed Ignition Control Troubleshooting RED Steady ON Steady OFF Rapid Flash 1 Flash 2 Flashes 3 Flashes 4 Flashes 5 Flashes YELLOW Steady ON Blinking Steady OFF CONTROL LIGHT STATUS Control OK No power False flame or internal control fault Limit switch is open Pressure switch is open with inducer on Pressure switch is closed with inducer off Lockout due to failed ignition 115 vac amp neutral reversed or no ground Good Flame Signal Weak Flame Signal No Flame Signal Picture 14 Limit Switch 29 Power Line Polarity The hot side of the power line must be connected to the L1 for the control to be able to sense flame The control detects the reversal of hot and neutral When L1 and Neutral are switched or L1 is not present the control flashes 5 on the Status LED and locks out Interrupted Thermostat If the thermostat demand for heat is removed before the flame recognition period the control will run the inducer for the post purge period and de e
27. SI off The gas valve and inducer remain energized Polarity may be verified as follows 1 Turn power supply ON 2 Using a voltmeter check for voltage between the hot black and neutral white wire of supply circuit Reading should be Line Supply Voltage GROUND Check for voltage between the neutral white wire and ground wire of the supply circuit Reading should be zero volts if line voltage is read polarity is reversed Double check by checking for OHMS voltage between the hot black WIS wrs wire and ground wire of the supply circuit 000V Vals O Prep GROUND Figure 22 Polarity and Ground 28 Steady heat Control inputs are continuously monitored to ensure limit and pressure switches are closed flame is established and the thermostat call for heat remains Post purge When the thermostat demand for heatis satisfied the control de energizes the gas valves The inducer output remains on for a 30 second post purge period Blower off delay The indoor blower motor is de energized after a 120 second blower off delay Blower timing begins when the thermostat is satisfied COMPONENT PARTS TROUBLESHOOTING Polarity and Ground The furnace will not operate if loss of ground occurs Every effort should be made at the installation to provide a good ground If old 2 wire romex exists it should be replaced with a 2 wire w ground A cold water li
28. Thermostat Off Thermostat on Break R to W call for heat R to W Main Blower vy Main Blower Flame Proving Gas Valve Factory Set gt gt at 120 seconds Inducer Igniter nnnununa Inducer 0 45 75 82 112 0 30 120 81 Elapsed Time Line Seconds Elapsed Time Line Seconds NORMAL START UP SEQUENCE NORMAL SHUT DOWN SEQUENCE Normal Start Up 1 Close R to W circuit The inducer motor is energized 2 After a 45 second pre purge the igniter is energized 3 After a 30 second heat up the gas valve is energized The igniter remains on during the first 6 seconds Gas valve will be de energized at 7 seconds if flame is not proved 4 After 30 seconds the main blower is energized Total elapsed time 105 seconds Normal Shut Down 1 Break R to W circuit 2 After 30 seconds the inducer is turned off 3 After 90 seconds the main blower is turned off 120 seconds after gas valve
29. X8 1210 1330 1160 1270 C UNITS 1110 1210 1070 1160 1010 1090 3 4 HP 4 054 10x 8 0 2 900 1110 1450 1850 870 1070 1420 1700 4 POLE 0 3 860 1080 1410 1810 840 1050 1380 1650 0 4 830 1040 1370 1760 820 1030 1350 1630 D UNITS 0 5 790 1020 1340 1730 780 1010 1320 1590 0 6 770 990 1320 1700 760 980 1290 1550 Table 2 Blower Performance Data g Wiring materials located in the return duct system shall conform to Articles 300 22 of the National Electrical Code ANSI C1 NFPA 70 h Gas piping is notrunin or through the return duct system i Test the negative pressure in the closet with the air circulating fan operating at high speed and the closet closed The negative pressure is to be no more negative than minus 0 05 inch water column j For floor return systems the manufactured home manu facturer shall affix a prominent marking on or near the appliance where it can be easily read when the closet door is open The marking shall read k Airconditioning systems may require more duct register and open louver area to obtain necessary airflow Use NORDYNE s certiduct program to determine proper duct size for A C Air Distribution Systems For proper air distribution the supply duct system must be designed sothatthe static pressure measured externaltothe furnace does not exceed the listed static pressure rating shown on the furnace rating plate
30. and sequence of operation for further details Then disconnect blower molex plug and check for voltage at plug If voltage is available and motor does not start replace motor If power is not available check back through power source and combustion blower relay contacts See wiring diagram Combustion Motor Assembly Replacement If usingthe information from above you have determinedthe combustion motor assembly needs to be replaced use the following procedure 1 Disconnect Molex plug and pressure switch hoses 2 Remove screws from the top and break silicone loose from orifice ring on top side of ventor assembly See Figure 15 Inlet pipe may also break loose this is normal 3 Remove screws from bottom of assembly and remove the whole assembly 4 Mountnew assembly reattach screws removed step to bottom Silicone around bottom either before or after installation of combustion air blower 5 Re silicone orifice ring and combustion air pipe and reinstall screws removed in step 2 to top 6 Reconnect Molex plug and pressure switch hoses from step 1 and test Pressure Switch The M1G 077 090 uses adifferential type pressure switch The purpose of this switch is to insure that agood supply of combustion air is suppliedtothe burner The combustion blower creates a differential in negative pressure less than atmospheric pressure across the orifice ring The switch is normally open and closes on a drop in pressure read in n
31. ator setting is 0 4 Refer to the thermostat literature for additional infor mation Blower Plug To Combustion Five conductor thermostat wire is recommended for 24 volt Blower or low voltage circuit 2 wire is required for furnace only 5 wire Poner for heating and optional cooling systems Entry Once the furnace is installed check the thermostat anticipator against the nominal setting of 0 4 1 Connect the milliamp meter in series with the W circuit On Auto Switch i Heating To Gas Valve 2 Energize call for heat Models Only or Burner 3 Read the value of the milliamps Figure 5 Control Panel All Models 4 Adjustthe heat anticipator of the thermostat to the value read on the milliamp meter T STAT Recommended T STAT Wire If the heat anticipator is set too high the furnace may delay in Wire Gauge Length Unit to T STAT coming on 2 Wire 5 Wire Heating Heating Cooling If the heat anticipator is set too low the furnace may cycle 24 55 25 frequently and not provide the desired comfort level 22 90 45 20 140 70 18 225 110 Table 4 Thermostat Wire Gauge Field Line Voltage Field Supplied Wiring Fused Service Panel Connector Factory Line Panel N Voltage Wiring Black Hot Z gt
32. ch opens the gas valve and ignitor will be de energized the indoor blower motor will run on heat speed and induced draft motor will run continuously Control status LED flashes 1 When the switch re closes the induced draft motor will run through post purge and the indoor blower will run through the selected fan off delay The control will return to normal operation after the blower off delay is completed Pressure Switch The control shall ignore pressure switch openings of less than 1 second the gas valve will momentarily de energize while the pressure switch is open this may cause a loss of flame To preventpressure switch faults from being treated as flame losses the control checks to see if the pressure switch has been 30 10 11 open momentarily within 2 seconds prior to the flame loss If the pressure switch was open any time within the 2 seconds prior to a flame loss the control assumes the flame loss was due to the open pressure switch and responds as described below If the pressure switch opens for more than 1 second after flame has been established the control shall de energize the gas valve run through a normal 30 second post purge and selected heat blower off delay When the blower off delay is complete the control shall start an ignition sequence if the thermostat is still calling for heat If the pressure switch opens for more than one second during a pre purge or inter purge the control s
33. connectthe hose going to the top connection If switch closes there is too much negative pressure being created on the inlet side Look for air inlet restriction 2 Ifthere is aheatexchanger restriction or exhaust restriction any restriction after motor it will cause alack of negative pressure If flow out of chamber exhaust is poor no air will be drawn in Clean chamber and recheck 3 If motor is not running no negative will be created and assembly will have to be replaced See combustion air assembly replacement Burner Assembly In order to perform procedures such as inspecting for presence of LP gas in chamber changing the thermocouple cleaning of pilot and burner and inspecting the heat exchanger the burner assembly must be removed Changing Complete Burner Assembly 1 GasLine Removethe furnace door then disconnect and remove the gas line from the valve body by using two backup wrenches Be careful not to damage the pipe threads or introduce dirt into the gas line 2 Wiring Leads Remove the two low voltage wiring leads from the valve body by carefully pulling them off the connectors Becareful notto damage or dirty the connector ends 3 MainBurner Mounting Plate Using aphilips screwdriver remove the screws that hold the main burner mounting plate to the furnace 4 Burner Assembly Slide the burner assembly out from the furnace 5 Reverse procedure to reinstall NOTE Be sure to install the gasket If gask
34. crews is located through the combustion air box on the right 8 Lift up divider panel out of side cabinet lances 9 Support the underside of the heat exchanger with a board 10 Remove top collector panel NOTE Two screws attach through top of cabinet 11 Remove the other eight screws in the top of the cabinet that hold the combustion air box 12 Remove heat exchanger and replace 13 Reverse steps one through eleven to reinstall NOTE Be sure to install all new gaskets from gasket replacement kit 14 Start up and check out for proper operation ooRomNm Figure 25 Heat Exchanger WIRING DIAGRAM 0 6860 jeuBis ewe 4 J440 peeis jeubig eure J poog NO peeis MOTI3A HOLIMS 3unssaud ou R IMA GLL seusel4 9 uoniuBi enp1noyoo X seuselj p HATVA SES zaida APZ jo JOONPU S YOIMS eJnsse d seuse j4 uo Jeonpul uedo si uoiMs eJnsseJg seuse 4 2 060 220 AIN LIN 13911 uado s uois ysej4 1 pue YIN LIN 10 use J pidey pauinbai si SONS Jamod ON 440 peeis peedsninui e HOLINSI MO 104U0D peeis ji SNLVLS LHDIT IOHLNOO 1VOINLOATS
35. ctrical not be less than 235 square inches or 390 square inches field wiring for 5 ton ready M1 Furnaces f Units have been investigated under standards UL 307A The total free area of openings in the floor or ceiling amp B ANZI21 47a CAN 2 3a 1995 and CSAB140 10 registers serving the return air duct system must be at least 352 sq in At least one register should be located 2 CIRCULATING AIR SUPPLY whereitis notlikely to be covered by carpeting boxes and other objects e Materials located in the return duct system must have a RETURN AIR PROVISIONS flame spread classification of 200 or less This includes a U S A home manufacturers shall comply with all of the closet door if the furnace is in acloset following conditions to have acce pianie rein air systems for f Noncombustible pans having 1 upturned flanges are closet installed forced air heating appliances located beneath openings in a floor duct system HP Wheel Coil ESP WITHOUT COIL WITH COIL Poles Units Speed Size In W C Low Med Lo Med Hi Low Med Lo Med Hi High 1 8 HP 1 024 0 1 730 9X 7 5 0 2 680 0 3 610 056 H A 0 4 550 UNITS 0 5 450 0 6 330 1 5 HP 1 030 0 1 950 850 9X 7 5 0 2 910 810 066 A 0 3 850 730 070 0 4 780 670 UNITS 0 5 680 580 0 6 570 480 1 4 HP 1140 10x8 1110 077 H B 1050 090 H B 990 086 B 930 UNITS 870 1 3 HP 960 1210 10x8 940 1170 056 890 1110 070 850 1050 UNITS 790 980 730 900 1 2 HP 1220 1340 11
36. e a 100 shut off type and will fail safe if for some reason the gas is turned off The valve is a step open type for M1G models which means it opens to a low fire position and after 14 seconds steps open to high fire A small orifice is placed in the gas passage to delay the build up of the working pressure A minimum of two minutes pause time is required between cycles to allow the orifice time to exhaust all working gas from the diaphragm chamber and obtain full dwell time on subsequent cycles Factory set nominal dwell time is approximately 14 seconds and is not field adjustable Venturi Assembly Figure 16 Burner Assembly with Venturi Assembly 20 Testing Operating Pressure a Remove furnace door and set the gas valve in the OFF position b Usinga3 16 Allen wrench remove the plug from the right side of the valve c Install the barbed adapter in the plug hole Tighten by hand at first then with an open end wrench Do not overtighten d Install the hose and manometer to the barbed fitting Be sure to check all connections for leaks e Light the pilot by following the instructions on the furnace and set the gas valve switch to the ON position f With the valve in the ON position set the thermostat above roomtemperature so the furnace will run throughout the test procedure g With the furnace operating check for valve staging The operating pressure sh
37. egative inches of water column Silicone Figure 15 Combustion Air Blower Under normal operating conditions once the ventor motor builds up to speed sufficient differential negative pressure approximately 0 30 wc willbe created to close the differen tial pressure switch and keep it closed the whole heating cycle Under abnormal conditions such as ventor motor failure or restricted air inlet or vent sufficient differential pressure will not be created Pressure switch check out procedure 1 Remove orange wires from pressure switch Place tees in the bases connecting pressure switch to combustion blower assembly 2 Connect a differential pressure gauge magnehelic or equivalent to the tees The magnehelic connection marked low connects to the lower tee and the one marked high connects to the top tee 3 Start motor 4 Negative pressure created by the forced draft motor must be greater than 0 30 w c for the switch to close 5 Use the ohm meter to check for continuity across the switch 6 If continuity is established switch has closed If ohm meter shows infinite reading and a pressure of 30 w c orhigheris present switch isopen and mustbe replaced If the pressure differential reading will not pull down to 30 W C possible causes could be 1 Restriction in air inlet pipe this causes a greater negative atthe inlet side connection This will actto open switch To prove this dis
38. ent sealed combustion downflow heating appliances for manufactured mobile homes recreational vehicles and for use in residen tial modular commercial construction The furnace must be located so that venting can be properly achieved A cabinet models may be installed with Optional Coil Cabi net Model 91 1969 for air conditioning B cabinet models are factory equipped with a built in coil cavity Multi speed blower assemblies See Accessories have been certified for field installation in M1 Series furnaces An air conditioner can be easily field installed with M1GH Series furnaces if used in conjunction with certified 2 wire relay box p n 903092A or 4 5 wire relay box 902898A INSTALLATION STANDARDS Installer shall be familiar with and comply with all codes and regulations applicable to the installation of these heating appliances and related equipment In lieu of local codes the installation shall be in accordance with the current provisions of one or more of the following standards Furnace Input Output NUS E S P Pilot Ignitor Comb A C Ready Model No matuh mat In ae Burner Direct Blower Tons pi M1MB 077 77 1 077 77 M1MD 077 77 M1MB 090 90 M1MC 090 90 M1MD 090 90 Electrical Supply 120 Volts 60 Hz 1 Ph Fuse or Breaker 15 Amps Temperature Rise 45 to 75 F High Altitude See Table 7 i x 3 x 3 x 4 x 5 x 3 X 3 4 x 5 x 2 x x 3 X x 4 x x 5 x 21
39. et becomes damaged or torn a replacement gasket kit is available Contact your distributor for part number WARNING Before removing burner assembly shut off all gas supply and electrical power to the furnace at the main shut off Lower Lesser Differential Negative Pressure Than Closing Pressure Insufficient negative pressure measured at the combustion blower may be caused by 1 Restriction on outlet side of combustion blower blocked flue or debris building up in flue Leak lack of restriction on inlet side Inducer inlet leaking inducer blower props loose or not attached or wrong restrictor orifice To test for restriction in outlet pipe exhaust to verify problem is outside of furnace disconnect exhaust for test period only and start furnace If furnace starts look for problem in vent pipe Reconnect after testing Higher than normal negative pressure at top connection acts to open switch may be caused by 1 Restricted combustion air inlet pipe 2 To verify if problem is in inlet pipe disconnect pressure switch hose at top connection and start furnace If furnace starts look for problems men tioned above in inlet pipe Note top connection acts to open contacts on differential switch NOTE Inlet Pressure Outlet Pressure Differential Pressure Table 9 Lower lesser Differential Negative Pressure Than Closing Pressure 19 Gas Valve The gas valves for the gas furnaces ar
40. hall wait for the pressure switch to close The purge time re starts when the pressure switch closes The control status LED will flash 2 If the pressure switch is closed when the call for heat occurs the control will begin to flash 3 on the status LED after 10 seconds and wait indefinitely for the pressure switch to open Flame sense Flame is normally sensed through the hot surface ignitor using flame rectification Open circuit flame sense voltage should be approximately 120 VAC line voltage Minimum flame current required to sense flame is 0 5 microamps DC Normal microamps is 3 or higher To test install microamp meter in series with ground 9 pin If flame light is on solid microamp signal is atleast 1 microamp If flame light is blinking flame signal is between 0 5 and 1 microamp indicating a weak signal Check for ignitor positioning and proper ground Undesired Flame If flame is sensed longer than 4 seconds while the gas valve is de energized the control shall energize the induced draft motor and indoor blower on heat speed When flame is no longer sensed the induced draft motor will run through post purge and the indoor blower motor will run through the selected heat fan offdelaytime The control willdo a softlockout but will still respond to open limit and flame The Status LED will flash rapidly when lockout is due to undesired flame Lockout The control shall not initiate a call for heat or call for conti
41. he NORDYNE Air Conditioner Limited Warranty Split system units with vertical discharge for quiet operation connect to the NORDYNE cooling coil furnace optional coil cavity required with A model furnaces Figure 12 Coil Cavity Damper Figure 13 Damper without Coil Cavity All Weather Cap Roof Jack Accessories 1 In case of high wind or icy conditions a 903656 all weather cap may be needed See Pilot Outage section 2 n regions where snow can accumulate and cover any portion of the roof jack up to two optional external extensions can be added part 901937 each 16 long 13 Standing Pilot Model M1G Furnace Sequence of Operation Troubleshooting Wiring Diagrams Troubleshooting Sequence M1G 056 070 Power up Selector Switch Power On Call for heat Check voltage t stat closes R W at WxC 8 Yes Check incoming power supply to at gas Nod Check circuit from secondary furnace and vas voltage through all safety switches selector switch Yes to gas valve Gas valve opens No Pilot lit No Relight pilot first stage low fire Consult Pilot Outage Yes Problems in service manual Yes 24 Volts at Gas Valve Lever in ON Position Inlet gas pressure OK Yes 14 second second stage No high fire Replace Valve Yes Air Circulating Yes Blower Starts Fan Switch Power at closes at 115 Motor No Yes Replace Replace Switch Mo
42. kage On new homes make sure no building materials fell in the top air inlet or exhaust Also remove top and make sure no seams have opened up on roof jack assembly On the M1G furnace natural draft model the airinletlimittripping is caused from a unbalanced draft which means the air inlet becomes a better flue than the flue itself Check out Procedure Is furnace filter clean If furnace is installed in closet what is the louver open area The installation instructions state the minimum open area required is 235 sq in or 390 sq in for 5 ton Inspect roof jack for internal blockage Inspect inside of upper combustion air box for debris With burner removed reach inside lower air box into com bustion air chute to check for debris insulation roofing material drywall etc and look in the bottom of the heat exchanger for debris Approx Length Model Number Below Flashing F S AW T 1523 0 2 4 A S 15 23 F S AW T 2135 0 2 4 A S 21 35 F S AW 1 2747 0 2 4 A S 27 47 F S AW T 3563 0 2 4 A S 35 63 F S AW T 5195 0 2 4 A S 51 95 AW 27 47 2 FLUE STEEL TYPE A ALUMINIZED S STAINLESS FLASHING RISE 0 F F FLAT FLASHING J S SLANT FLASHING AW ALL WEATHER MIN ADJ LENGTH BLANK NON TRANSIT T TRANSIT MODE LENGTH 2 2 eng 4 4 12 Table 3 Roof Jack Assemblies Is gas orifice the proper size f
43. l to use the correct height for reinstallation Disconnect thermocouple from gas valve and pilot assembly 4 Slide thermocouple out through hole left after pilot close off plate was removed 5 Reinstall new thermocouple and reverse steps from above Note Use hand to tighten thermocouple in gas valve plus 1 4 turn with wrench Do not overtighten Venturi Burner Assembly The burner assembly consists of the burner venturi and spreader If burn through or other burner problem occurs follow these steps to replace the burner 1 Follow the steps under changing burner assembly Disconnect pilot assembly by removing the two screws holding pilot assembly and shield 3 Remove the two phillips screws holding the burner from the round burner plate Note that one is removed from the front side and one from the back side 4 Remove burner and flame spreader assembly 5 Install the new one by reversing steps 1 through 4 6 Startup and test Gas Valve Replacement 1 Turn off gas and electric 2 Disconnect the two low voltage wires 3 Disconnectpilottubing and thermocouple from gas valve 4 Remove the two screws from the gas valve mounting plate Remove gas valve and remove gas valve mounting Remove spud holder threaded into valve Repipe dope spud holder and tighten into new valve Reverse steps through 5 and test Fan Switch Picture 5 The fan switch is a temperature actuated normally open switch that
44. lower assembly slightly and swing outto left Loosen set screw on blower hub Remove screws holding motor to blower housing akwWN gt Band Around Mount 5 D Torsion Mount Picture 23 Blower Assemblies 34 6 Remove motor and replace NOTE Some motors are torsion flex mount and some are band around mount See picture below 7 Reverse steps 1 5 to reinstall Note Be sure to tighten blower set screw on flat of motor shaft Heat Exchanger Replacement The heat exchanger is the largest and most expensive item in the furnace Before replacing the heat exchanger make certain it is the problem Call the technical service department if you have any uncer tainty about a heat exchanger failure Heat exchangers can become sooted up due to debris in top of furnaces improper conversion or not being converted to LP See troubleshooting section on flue and conversion section of this manual This condition is not covered under warranty See page 22 of this manual To Test Heat Exchanger Note The furnace does not have to removed to replace the heat exchanger Change Out Procedure Disconnect all gas and electrical power to furnace Disconnect flue Remove burner assembly Remove combustion air pipe and combustion blower Remove blower assembly Remove blower deck panel NOTE Panel will be difficult to remove with furnace in alcove 7 Remove front panel NOTE One of the panel s
45. nd by Switch for next cycle 16 7 Standing Pilot Model M1G SEQUENCE OF OPERATION FOR STANDING PILOT a Onacallfor heat the thermostat contacts close supply ing 24 VAC to the gas valve b When the gas valve is energized it steps open at a reduced flow and opens fully after approximately 14 seconds c Whenthecallforheatis satisfied the thermostat contacts open the gas valve shuts off gas flow SEQUENCE OF OPERATION FOR STANDING PILOT W INDUCED DRAFT BLOWERS a Onacallforheat the thermostat contacts close supply ing 24 VAC to the relay b The relay contacts close and energize the induced draft motor c When the motor reaches full speed the pressure switch closes and energizes the gas valve d When the gas valve is energized it steps open at a reduced flow and opens fully after approximately 14 seconds e Whenthe callforheatis satisfied the thermostat contacts open the gas valve shuts off gas flow and the induced draft blower stops TROUBLESHOOTING Polarity and Ground The furnace will not operate if loss of ground occurs Every effort should be made at the installation to provide a good ground If old 2 wire romex exists it should be replaced with a 2 wire w ground A cold waterline could be used provided that the connection or grounding occurs before any di electric fittings and provided no plastic pipe is used inside or outside the building Polarity may be verified as follows 1 Turn power suppl
46. ne could be used provided that the connection or grounding occurs before any di electric fittings and provided no plastic pipe is used inside or outside the building Transformer See Figure 21 The transformer supplies control voltage 24 vac by stepping down the supply pri mary voltage from 115 vac to 24 vac secondary voltage Transformers are rated by VA V is the volt amp or total wattage the secondary can handle When a transformer is replaced the VA should be of an equal or greater value Check out procedure 1 Using a volt ohmmeter on at least 115 vac scale 2 Measure the voltage on the control board terminals XFMR amp NEUTRAL 3 If voltage is 115 vac measure the voltage at terminals marked 24 vac amp Com located in the center of the control board 4 f 115 vac is measured at XFMR amp NEUTRAL but voltage is presentat 24 vac amp Com replace transformer Picture 11 M1M Transformer Transformers open on primary indicate low voltage short circuit Transformers open on secondary indicate an overload a current draw that exceeded rating Low Voltage Wiring Install the thermostat per the manufacturer s instructions The low voltage 24 vac connections from the thermostat are made at the pigtail wires coming off the control board in the furnace See Figure 23 for the proper connections for heating only two wire and heating cooling four wire applications The recommended minimum
47. necessary to convert the pilot orifice g For Honeywell gas valves with the regulator converter Figure 8 check for the letters NAT or LP onthe pressure regulator cap Unscrew the cap invert it replace and tighten until snug h For the Robertshaw gas valve with the regulator con verter Figure 9 remove the black cover and unscrew the converter located on top of the gas valve Invert the converter For LP the red ring will be located at the bottom andthe LP stamping on the converter will appear right side up Then screw converter back into the regu lator hand tight plus 1 8 turn and replace the black cover onto the converter top to protect the threads i Reassemble the burner assembly into the furnace j Reconnect the gas piping and electrical wires to the gas valve k Openthe manual shut off valve and follow the FURNACE START UP procedure as outlined previously in this manual to put the furnace into operation NOTE The pilot flame is adjustable by turning the adjustment screw located on the gas valve with a small screwdriver See Figure 10 LIGHTING AND FURNACE SHUTDOWN GENERAL ALL MODELS Read the safety information on the front page of these installation instructions before lighting furnace DO NOT ATTEMPT TO LIGHT FURNACE IF YOU SMELL GAS SAFETY INFORMATION FOR YOUR SAFETY READ BEFORE LIGHTING Honeywell Valve PRESSURE REGULATOR
48. nergize all outputs Ignition Re Try If flame is not established on the first trial for ignition period the gas valve is de energized and the inducer remains energized for an inter purge period of 30 seconds The ignitor is then re energized and the control initiates another trial for ignition This sequence repeats for up to 5 trials for ignition Ignition Re Cycle Flame must not be sensed for 1 second before the control responds to a loss of flame If flame is established and maintained during the trial for ignition period and then flame is lost the gas valve is de energized within 2 seconds the induced draft motor continues to run and the control begins timing the 45 second inter purge delay The indoor blower motor will be energized and or remain energized on heat speed for the selected delay off time When the inter purge delay is over the ignitor is re energized and the control initiates another ignitor warm up and ignition activation period The control will re cycle up to 5 flame losses 4 re cycles within a single call for heat before going to lockout Call for Continuous Fan Cooling When a thermostat call for continuous fan G without a call for heat or cooling the indoor fan is energized on the COOL speed after a 25 second delay If a call for heat W occurs during continuous fan the blower will de energize A call for fan is ignored while in lockout Limit Switch Operation Any time the limit swit
49. nuous fan while in lockout A call for cooling operates as normal The control will still respond to an open limit and undesired flame Lockout will automatically reset after 1 hour Lockout may be manually reset by removing power from the control for more than 1 second or removing the thermostat call for heat for more than 1 and less than 20 seconds The 20 second time limit prevents electronic thermostats from automatically resetting lockout Power Interruption The control will not interrupt its operational sequence from power interruptions less than 80 mS in duration Relay outputs will momentarily de energize during the interruption Power interruption greater than 80mS may cause the control to interrupt the operating sequence and resume as if power was first applied All power interruptions of any duration are to be self recovered and not result in a condition that could cause lockout 12 Conirol Internal Diagnostics a Internal microprocessor tests The software will perform tests of the internal microprocessor hardware as much asis practical A detected failure in internal hardware will result in lockout with the Status LED blinking rapidly b Flame sense circuitry diagnostics The integrity ofthe flame sense circuitry is constantly monitored by the microcontroller The control will lock out with the status LED flashing rapidly if a fault is detected in the flame sense circuitry c Failed gas valve relay If the control
50. or from the nearest register monitor the level for an increase while the unit runs Single digits of CO are common butcigarette smoke etc can have an impact on the level A rapid increase in the CO level while the furnace is running is not normal If this occurs inspect the heat exchanger Note The furnace does not have to removed from its alcove to replace the heat exchanger Be sure to order the replace ment gasket kit along with the heat exchanger It contains all gaskets used in the furnace Change Out Procedure 1 Disconnect all gas and electrical power to furnace 2 Disconnect flue 3 Remove burner assembly 4 a M1G 056 070 Only Remove combustion air pipe b M1G 077 090 Only Remove combustion air pipe and combustion blower Remove blower assembly Remove blower deck panel NOTE Panel will be difficult to remove with furnace in alcove 7 Remove front panel NOTE One of the panel screws is located through the combustion air box on the right Lift up divider panel out of side cabinet lances Support the underside of the heat exchanger with a board 10 Remove top collector panel NOTE Two screws attach through top of cabinet 11 Remove the other eight screws in the top of the cabinet that hold the combustion air box 12 Remove heat exchanger and replace 13 Reverse steps one through eleven to reinstall NOTE Be sure to install all new gaskets from gasket replacement kit 14 Start up and check
51. or the gas in use Check manifold gas pressure at low fire 14 seconds nominal before it steps to normal high fire The compression fitting on the pilot tube must be tight sthe burner aligned perpendicular to the burner mounting plate APPLICATION OF ALL WEATHER CAPS In most cases when a pilot is blown out during windy condi tions an all weather cap will take care of this problem Extension s will also help see Pilot Outage See Accessory Chart for part numbers All weather caps are used in areas of extreme cold 10 or lower for long periods of time This causes ice to form and block combustion air Replace the standard crown with the optional all weather cap Follow instructions with the new all weather cap See Accessories section for part number a Ifthe roof jack crown 15 covered or blocked with snow the furnace will not operate properly If the home is located in regions where snow accumulation exceeds 7 HUD snowload zones use an external roof jack extension p n 901937 b M1 furnaces may be used with roof jacks as tall as 170 except M1M 056 models which are limited to 120 Internal roof jack extensions p n 901935 10 p n 903107 18 can be used to increase roof jack height All connec tions inside the home must be made below the ceiling This joint Roof Jack may ba above ceiling Flashing Flat Roof vA Ceiling Cavity A Ceiling B Flue Pip Y Combustion A
52. otor Remove wires going to motor Remove Phillips screw s on left side Raise entire blower assembly slightly and swing out to left Loosen set screw on blower hub Remove screws holding motor to blower housing Remove motor and replace NOTE Some motors are torsion flex mount and some are band around mount See picture below 7 Reverse steps 1 5 to reinstall Note Be sure to tighten blower set screw on flat of motor shaft oo0Rom Torsion Mount Picture 10 Blower Assemblies 21 Heat Exchanger Replacement The heat exchanger is the largest and most expensive item in the furnace Before replacing the heat exchanger make certain it is the problem Call the technical service department if you have any uncer tainty about a heat exchanger failure Heat exchangers can become sooted up due to debris in top of furnaces improper conversion or not being converted to LP See troubleshooting section on flue and conversion section of this manual This condition is covered under warranty To Test Heat Exchanger Several methods may be used to test or inspect for heat exchanger flaws 1 Remove the blower and burner Visually inspect the heat exchanger with a mirror If you find a crack or hole in any part of the heat exchanger replace with out delay 2 When the blower starts observe the flame If there is a disturbance in the flame inspect and determine the cause 3 Using a CO detect
53. ould be approximately 3 5 WC for Natural Gas 10 WC for LP gas Pilot Assembly Thermocouple and Venturi Burner The pilot lights the main burner The thermocouple generates around 30 MV unloaded unscrewed from valve and around 15 MV loaded screwed into valve See gas valve and pilot outage section for troubleshooting The pilot orifice is not changed when furnace is converted to LP see conversion section If the flame is more than about 1 in height it can be adjusted using the pilot adjustment screw Turn the screw clockwise to decrease the flow rate counterclockwise to increase it Note Do not confuse the pilot adjustment screw with the pressure regulator which in creases by turning clockwise and decreases by turning coun terclockwise To clean pilot or service thermocouple or burner 1 Remove burner 2 Remove pilot assembly screws and pilot shield 3 Remove pilot tube from pilot assembly 4 Inspect pilot assembly tap out pilot orifice and clean or replace if plugged 5 Replace the pilot tube shield assembly screws and burner Re start and test Pilot Assembly Thermocouple Picture 9 Pilot Assembly and Thermocouple To change thermocouple 1 Follow the same steps used to remove pilot assembly 2 Remove pilot tube close off plate by removing the phillips screw on the burner plate 3 Note the height of the thermocouple in relationship to the pilot before removal Itis critica
54. out for proper operation 22 Figure 17 Heat Exchanger Roll Out Switch M1G 056 amp 070 The furnace is protected by a manual reset safety switch located on the bottom left hand side of the combustion pipe A draft imbal ance or improperly staging valve can cause this switch to open up Check for poor draft or blockage in the heat ex changer to correct draft imbalance Pilot Outage Pilot outage can occur because of either a mechanical internal or environmental external problem The frequency and conditions that exist will be important information in solving a pilot outage problem Most mechani cal problems will result in a situation where pilot can not be lit at all or goes out with the first cycle or shortly thereafter The environment around the furnace or home will be trickier to diagnose and usually will have infrequent occurrences of pilot outage such as once a week only on windy days etc Since most pilot outage problems fall under one of these two situations our troubleshooting will be divided up into these two areas See Pilot Outage chart next page Pilot Outage Chart Mechanical Internal to Furnace Problem 1 No pilot Flame Possible causes No inlet gas pressure Plugged pilot orifices Solutions Check sources Clean or replace orifices 2 Pilot lights with button held but goes out when released 3 Pilot lights OK goe
55. r exhaust restriction any restriction after motor it will cause a lack of negative pressure If flow out of chamber exhaust is poor no air will be drawn in Clean chamber and recheck 3 If motor is not running no negative will be created and assembly will have to be replaced See combustion air assembly replacement Hot Surface Ignitor The hot surface ignitor is helical in shape and is located approximately 5 16 in front of the burners Its function is to ignite fuel at the appropriate time in the sequence The hot surface ignitor used is manufactured by CARBORUNDUM NOTE Special care should be taken when handling the ignitor You should never touch the ignitor surface Grease or dirt from your hands will shorten the ignitor s life Check out Procedure 1 Unplug ignitor from 2 prong plug 2 Place a voltmeter on the proper scale at least 115 vac 3 Establish a call for heat 4 After approx 45seconds of induced draft motor operation the ignitor should see line voltage If voltage is present replace the ignitor See Figure 41 If no voltage is present replace control board Picture 20 Hot Surface Ignitor Picture 21 Ignitor and Voltmeter 7 The ignitor may also be ohmed out The ignitors usually range from 125 to 150 ohms at 70 F 21 C 8 Be sure when replacement ignitor is installed that it is approximately 5 16 from the burners Mishandling and misalignment
56. rious or even fatal not only to them but also to persons being served by the equipment If you install or perform service on equipment you must assume responsibility for any bodily injury or property dam age which may result to you or others We will not be responsible for any injury or property damage arising from improper installation service and or service procedures Application M Manufactured Home Furnace Series Fuel Type of Combustion G Gas Direct Vent Pilot Burner Natural or Forced Draft M Gas HSI Forced Draft B Gas Gun Burner S Oil Gun Burner Comfort Model H Heating A Heating A C Ready B A C Ready 3 Ton A C Ready 4 Ton D A C Ready 5 Ton M 1 G H 056 A BW Door Color W White G Gray Cabinet Size A 20 x 24 x 56 B w Coil Cavity 20 x 24 x 76 Electrical Code A 1PH 60 Hz 120 VAC Heating Capacity Input BTUH 000 Serial No Identification Model Series M 1 G 9807 05432 Production Code Production Year Month NOTICE TO INSTALLER Installer is advised to follow carefully all instructions and warnings in this manual to insure maximum performance safety and operating efficiency of these appliances Improper installation may create hazardous conditions and will void the appliance warranty 1 SPECIFICATIONS GENERAL DESCRIPTION M1 Series gas and oil furnaces are listed direct v
57. s as supplied with the appliance must be replaced use 105 C Thermoplastic type wire or its equivalent SUPPLIED BY INSTALLER FIELD 115 FIELD 24V HEATING COOLING SINGLE R BLUE CONNECTOR HOUSING CAP a HI LIMIT 3A FUSE BLACK GRAY TRANSFORMER H 5 24v ORANGE ORANGE BLACK WHITE GRAY ow D L LACK HIGH COMBUSTION FAN CONNECTOR HOUSING FURNACE ELECTRICAL BOX Jumper Wire M1GB Units Only Otherwise Hi Speed Connected to Blower Relay GAS VALVE PRESSURE SWITCH Figure 21 Standing Pilot with Induced Draft Furnace A C Ready M1G B C D 077 090 Models 25 Hot Surface Ignition System Model M1M Furnace Sequence of Operation Troubleshooting Wiring Diagrams Troubleshooting Sequence M1M Call for heat t stat closes Yes Inducer starts Yes 24 Volt C to Check for red light Check fuse on on circuit board on circuit board circuit board pe ete Pressure switch continuity M Is light blinking closes within 5 times 10 seconds pes Yes Polarity is reversed Switch L1 amp L2 Inducer pre purges for 45 seconds Yes Ignitor heats up and glows for 30 seconds Gas valve open Yes Do Burners Light
58. s out when main valve comes on or shortly thereafter 4 Pilot goes out when main valve comes on or shortly after but only on cold start up first cycle only Pilot not contacting 3 8 to 1 2 top of thermocouple Thermocouple burned through Check for proper millivolts see thermocouple section for procedure Gas valve not staging or too high inlet gas pressure Restricted air inlet or exhaust pipe No baffle prior to April 1999 Gas valve not staging Clean and or adjust pilot Check inlet gas pressure Replace thermocouple if defective Millivolts OK Replace gas valve Replace valve lower gas pressure at regulator or house Clean out any debris Install baffle kit 903722 Replace gas valve 5 Pilot lights OK goes out when gas valve closes pulled out Gas valve closing improperly Pilot dirty or needs adjustment Replace valve Adjust or clean pilot Environmental external to furnace Problem 1 Goes out only when its windy or Barometric pressure drops suddenly 2 Goes out only when it snows Possible causes Roof jack termination too close to roof line causing downdraft Standard crown Roof Jack termination too low covering inlet Solutions Install optional extension kit to take both inlet and exhaust above roof peak Install optional all weather cap 903656 Install optional extension kit 901937 3 Goes out only in zero or sub zero weather
59. sure Switch Under normal operating conditions once the ventor motor builds up to speed sufficient differential negative pressure approximately 0 30 wc willbe created to close the differen tial pressure switch and keep it closed the whole heating cycle Under abnormal conditions such as ventor motor failure or restricted air inlet or vent sufficient differential pressure will not be created Under most circumstances when the pressure switch is not going closed insufficient differential negative pressure is not being created See Table 9 for opening and closing settings Pressure switch check out procedure 1 Remove orange wires from pressure switch Place tees in the bases connecting pressure switch to combustion blower assembly 2 Connect a differential pressure gauge magnehelic or equivalent to the tees The magnehelic connection marked low connects to the lower tee and the one marked high connects to the top tee 3 Start motor 4 Negative pressure created by the forced draft motor must be greater than 0 30 w c for the switch to close 5 Use the ohm meter to check for continuity across the switch 6 If continuity is established switch has closed If ohm meter shows infinite reading and a pressure of 30 w c orhigheris present switch is open and mustbe replaced If the pressure differential reading will not pull down to 30 w c possible causes could be 1 Restriction in air inlet pipe
60. t is essential that only competent qualified service personnel attempt to install service or maintain this product This Service manual was written to assist the professional HVAC service technician to quickly and accurately diagnose and repair most malfunctions of this product This service manual covers standing pilot and hot surface ignition gas burner models The overall operation of both of these models is essentially the same with the exception of certain controls which may be unique to each model This manual will deal with all subjects in a general nature i e all text will pertain to all models unless that subject is unique to a particular model or family in which case it will be so indicated Model Identification It will be necessary for you to accurately identify the unit you are servicing So you may be certain of approved diagnosis and repair See Unit Identification Below This manual was prepared by the senior Technical Service Department and the Communications Department A WARNING The information contained in this manual is intended for use by a qualified service technician who is familiar with the safety procedures required in installation and repair and who is equipped with the proper tools and testing instruments Installations and repairs made by unqualified persons can result in hazards subjecting the unqualified person making such repairs to the risk of injury or electrical shock which can be se
61. ting Jump out R to W at thermostat with 10 Loop Helex and measure current draw after blower starts Divide by 10 Example 4 Amps 4 set at 4 OR Set the heat anticipator according to the manufacturer s recommendations Limit Control Picture 5 This furnace is protected by two high temperature safety limit switches The auxiliary upper limit switch and the high temperature lower limit switch are automatic reset types If either limit trips the burner will shut off Check temperature rise and compare to specifications 45 to 75 F Picture 5 Fan and Limit Switch Combustion Air Relay The combustion air relay is used only on the M1G 077 090 On a call for heat the relay activates the combustion air motor The relay is energized through the thermostat from the W terminal It has a24VAC coil powered by the W and Common terminals 3 and 1 Terminals 4 and 2 are normally open contacts Combustion Air Blower The M1G 077 090 model uses a combustion air blower incorporated in series with the air inlet pipe Its purpose is to supply a forced draft method of combustion air The quantity of air is determined by the inlet orifice ring located on the inlet to the motor assembly 18 Upon a call for heat under normal conditions the combustion blower starts up and supplies combustion air to the chamber If motor does not start check to be sure call for heat is established See troubleshooting flow chart
62. tly and move left to OFF DO NOT FORCE e Wait ten 10 minutes to clear out any gas If you smell gas STOP Follow step d in the SAFETY INFORMA TION If you don t smell gas go to the next step f Find pilot follow metal tube pilot tube from gas control valve Open hinged fire observation door The pilot is foundatthe end of the pilot tube just left of the pilot shield g Slightly depress the gas control lever and move it right to the ON position and release then move itto the PILOT position h Move the control lever to SET and hold Immediately light the pilot with a match If this furnace is equipped with a Piezo Ignitor activate spark lever button several times until flame is visible through observation door Continue to hold the control lever for about one 1 minute after the pilot is lit Release the lever and it will spring back to the PILOT position Pilot should remain lit If it goes out repeat steps d through h above If the lever does not spring back when released stop and immediately call your service technician or gas supplier If the pilot will not stay lit after several tries move the gas control lever to OFF and call your service technician or gas supplier i Move the gas control lever left to ON j Turnonallelectric power to the furnace Set the thermo stat to Heat and or the desired temperature setting Set the On Off Fan switch to ON k Replace
63. to be used with either a 4 wire relay box p n 9028984 ora 2 wire relay box p n 9030924 Follow the instructions included with the relay box for proper installation Cooling Blowers If you are installing an AC system which exceeds the maxi mum AC capacity of your system a larger blower will have to beinstalled Ablower assembly may also need to be installed for high static pressure applications or crossover systems Refer to Blower Data for further information Part No Blower Motor Assembly A C Capacity Blower Wheel Motor Hp Ton 903412 10x 8 1 3 2 212 amp 3 903413 11x8 1 2 2 22 38 4 903414 10x 8 3 4 2 2 3 4 amp 5 Table 8 Field Installation Blower Assemblies Fan Timer Kit The M1G furnace uses a temperature activated switch type fan control The M1M uses a time delayed control so this information does not apply A fan timer kit may need to be installed with this type of switch if the following conditions exist 1 Very cold outside air temperatures being drawn in through the VentilAire system 2 Nighttime thermostat set back to avery low temperature 3 System is left off for extended periods of time The fan may be cycling during anormal call for heat For gas models make sure the gas valve is reaching high fire Ifthere are no problems with the firing rate install a Nordyne fan timer kit part number 903490 See instructions with kit for installa tion Since many factors outside our
64. tor Thermostat Satisfies Open R to W ed i Shut down Replace Thermostat Air Circulating No Fan Switch Blower Shuts Down opens at 95 Yes No Stand by Switch for next cycle Yes 15 Troubleshooting Sequence M1G 077 090 Combustion Blower Model Power up Selector Switch Power On Call for heat No Check voltage lt 2 X Refer to Low Voltage and ee ii at 1 and 3 on Limit Control sections es Combustion Relay Piae Combustion Refer to Combustion Air Blower power supply to Motor starts i and Blower Relay sections furnace and Y selector switch ais for troubleshooting Pressure Switch No ____ Refer to Pressure Switch section closes Yes Power at gas No Check circuit from secondary valve voltage through all safety switches Yes to gas valve Gas valve opens Pilot lit No Relight pilot first stage low fire Consult Pilot Outage section and chart Yes 24 Volts at Gas Valve Lever in ON Position Inlet gas pressure OK Yes 14 second second stage high fire Replace Valve Yes Air Circulating i Yes Blower Starts Fan Switch Power at closes at 115 Motor Replace Replace Switch Motor Thermostat Satisfies gt Open R to W Yes Es Shut down Replace Thermostat Air Circulating No Fan Switch Blower Shuts Down opens at 95 Yes No Sta
65. valve The maximum inlet pressure for the valve is 13 W C For L P gas pressure to the gas valve must be more than 11 W C but not more than 13 W C Pressure is reduced to 10 W C by the pressure regulator in the gas valve GAS CONVERSION This gas fired heating appliance was shipped from the factory for use with natural gas However the appliance can be converted for use with LP gas Use the following procedure for gas conversion of the burner ATMOSPHERIC AND DIRECT IGNITION FURNACES a Followthe instructions to Turn Off Gas to the Appliance b Disconnect the gas pipe union and the electrical wires connected to the gas valve c Remove the pilot tube and thermocouple from the gas valve M1G only d To remove the gas valve assembly remove screw s from gas valve bracket Gas valve and spud may be removed Orifice is located at the end of the spud M1G M1M e Replace the main orifice with the L P gas orifice supplied in the envelope located by the gas valve Check to insure the orifice size matches the nameplate NOTE For eleva tions over 2 000 feet use Table 7 to determine orifice size 10 On Off Fan Switch Control Panel Alt Fuel To Gas Line Entry Supply The furnace must be converted by a qualified technician Improper conversion can cause unsafe operation explosion fire and or asphyxiation f It is not
66. y ON 2 Using a voltmeter check for voltage between the hot black and neutral white wire of supply circuit Reading should be Line Supply Voltage GROUND Check for voltage between the neutral white wire and ground wire of the supply circuit Reading should be zero volts if line voltage is read polarity is reversed Double check by checking for voltage between the hot black wire and ground wire of the supply circuit OHMS MICRO GROUND Figure 14 Polarity and Ground Transformer Picture 3 AllM1G furnaces are protected by a fuse in the 24 vac circuit The transformer supplies control voltage 24 vac by stepping down the supply primary voltage from 115 vac to 24 vac secondary voltage All M1 transformers are rated at 30 VA VA is the volt amp or total wattage the secondary can handle When a transformer is replaced the VA should be at least 30 VA but no more than 40 VA Check out procedure 1 Using a volt ohmmeter on at least 115 vac scale 2 Measure the voltage at the primary side 3 Ifvoltageis 115 vac measure the voltage atthe secondary terminals marked 24 vac amp Com on the transformer 4 lf115vacis measured at primary butno voltage is present at 24 vac amp replace transformer 5 Fuse will blow if a secondary short occurs Transformers open on secondary indicate an overload a current draw that exceeded rating

690A-0999 M1 Series sm.p65

Contents

Download Pdf Manuals

Related Search

Related Contents