OUTDOOR ROOFTOP GAS-FIRED DUCT FURNACE
Contents
1. TOP VIEW Y la ell poco VA i iN Neoprene Washers Screws These Surfaces indicated with an asterisk in figures 8a amp 8b MUST be flush and sealed at all times to ensure the proper discharge of flue products from the unit These discharge flanges are equipped with special gasketing which must create an air tight seal connection around the louvers of the access panel Secure in place the access door to the discharge adaptor using the two screws and neoprene washers then tighten the grip D3505 latches see service access panel removal section Figure 8b bares Figure 8c DUCT SPECIFICATIONS Ductwork which is outdoors must be insulated and sealed to prevent water from entering either furnace or building through the duct Do not alter the flange connection for the duct attachment air may bypass and cause combustion problems Be sure to properly seal to avoid any air leakage refer to Figures 1 and 2 Ductwork connected to duct furnaces should have removable access panels on both the upstream and downstream sides of the unit These openings should be accessible when the unit is installed and should be sized so that smoke or reflected light can be observed inside the casing to indicate the presence of leaks in the heating equipment The covers of the openings should be2. e e 10 1 8 Connections E 257 Ss Eds 5 1 16 fe 129 am t 5 8 16 Typ _ B Anchor Hole i 4 102 Location Opening Typ 102 E aed ped I 13 16 21 Typ 22 Anchor Hole DFR3541A TFR3779 A Ce 4 d FE Location Chart 2 Performance and Specification Data F Nat L P INPUT OUTPUT Temp Rise Min Gas Gas Net Shipping CAPACITY RATING RATING EFF MIN MAX F Deg Static Clearance Inlet Inlet Weight Weight MBH BTU Hr BTU Hr CFM CFM C Deg in of Water in in in Ib Ib kW kW Min Max kg 100 100 000 80 000 80 823 2 469 30 90 2 7 1 8 1 2 1 2 202 221 29 3 23 4 0 388 1 165 17 50 0 50 181 92 100 150 150 000 118 500 79 1 219 3 657 30 90 2 11 1 4 1 2 1 2 228 247 43 9 34 7 0 575 1 726 17 50 0 50 286 103 112 200 200 000 158 000 79 1 626 4 876 30 90 2 14 1 2 1 2 283 304 58 6 46 3 0 767 2 301 17 50 0 50 356 128 138 2 250 250 000 197 500 79 2 032 6 096 30 90 2 22 1 4 3 4 1 2 3 4 309 330 73 2 57 8 0 959 2 877 17 50 0 50 565 140 150 E 300 300 000 237 000 79 2 438 7 315 30 90 2 34 3 4 1 2 OR 3 4 365 387 2 87 8 69 4 1 151 3 453 17 50 0 50 864 166 176 350 350 000 276 500 79 2 845 8 534 30 90 2 33 1 4 3 4 1 2 3 4 391 413 102 5 81 0 1 343 4 028
3. Close air shutter Open all manual gas valves Reduce pilot gas Refer to operation Replace orifice a Reset manifold pressure Refer to operation b Replace regulator section of combination gas valve or complete valve c Check with local gas sup plier for proper orifice size and replace Refer to operation H Yellow tip flame some yellow tipping on propane gas is per missible Insufficient primary air Clogged main burner ports Misaligned orifices Air shutter linted Insufficient combustion air Clogged draft hood flue collec tor amp Open air shutters Refer to operation Clean main burner ports Replace manifold assembly Check for dust or lint at air mixer opening and around the air shutter Clean combustion air inlet openings in bottom panel Refer to installation Clean draft hood flue collecter 23 Chart 6 Trouble Shooting continued SYMPTOMS POSSIBLE CAUSES CORRECTIVE ACTION J Floating flame Blocked heat exchanger Insufficient combustion air Blocked venting Air leak into combined cham ber draft hood or flue collector Clean heat exchanger 2 Clean combustion air inlet openings in bottom panel Refer to installation Clean flue Refer to installation Determine cause and repair accordingly Refer to installation K Burner wo
4. 17 50 0 50 845 177 187 400 400 000 316 000 79 3 251 9 753 30 90 2 38 3 4 34 1 2 3 4 427 459 117 1 92 5 1 534 4 603 17 50 0 50 984 194 208 100 100 000 79 000 79 813 2 438 30 90 2 7 1 8 1 2 1 2 200 219 29 3 23 1 0 384 1 151 17 50 0 50 181 91 99 150 150 000 118 500 79 1 219 3 657 30 90 2 11 1 4 1 2 1 2 223 242 43 9 34 7 0 575 1 726 17 50 0 50 286 101 110 m 200 200 000 158 000 79 1 626 4 876 30 90 2 14 1 2 1 2 270 291 58 6 46 3 0 767 2 301 17 50 0 50 356 123 132 250 250 000 197 500 79 2 032 6 096 30 90 2 22 1 4 3 4 1 2 3 4 296 317 73 2 57 8 0 959 2 877 17 50 0 50 565 134 144 9 300 300 000 237 000 79 2 438 7 815 30 90 2 34 3 4 1 2 OR 3 4 343 365 87 8 69 4 1 151 8 453 17 50 0 50 864 156 166 350 350 000 276 500 79 2 845 8 534 30 90 2 33 1 4 3 4 1 2 OR 3 4 369 391 102 5 81 0 1 343 4 028 17 50 0 50 845 167 177 400 400 000 316 000 79 3 251 9 753 30 90 2 38 3 4 3 4 1 2 3 4 405 437 117 1 92 5 1 534 4 603 17 50 0 50 984 184 198 ER 100H 100 000 80 000 80 1 235 3 704 20 60 2 71 8 1 2 1 2 199 218 29 3 23 4 0 583 1 748 11 83 0 50 181 90 99 150H 150 000 120 000 80 1 852 5 556 20 60 2 11 1 4 1 2 1 2 226 245 43 9 35 1 0 874 2 622 11 33 0 50 286 103 111 200H 200 000 160 000 80 2 469 7 407 20 60 2 14
5. INSTALLATION AND SERVICE MANUAL S RISM 9 J30 05380A OUTDOOR ROOFTOP GAS FIRED DUCT FURNACE NATURAL OR POWER VENTED ATTENTION READ THIS MANUAL AND ALL LABELS ATTACHED TO THE UNIT CAREFULLY BEFORE ATTEMPTING TO INSTALL OPERATE OR SERVICE THESE UNITS CHECK UNIT DATA PLATE FOR TYPE OF GAS AND ELECTRICAL SPECIFICATIONS AND MAKE CERTAIN THAT THESE AGREE WITH THOSE AT POINT OF INSTALLATION RECORD THE UNIT MODEL AND SERIAL No s IN THE SPACE PROVIDED RETAIN FOR FUTURE REFERENCE Model No Serial No SAVE THIS MANUAL FOR YOUR SAFETY The use and storage of gasoline or other flammable vapors and liquids in open containers in the vicinity of this appliance is hazardous FOR YOUR SAFETY If you smell gas N 1 Don t touch electrical switches N 2 Extinguish any open flame D 3 Immediately call your gas supplier ur AWARNING Improper installation adjustment alteration service or maintenance can cause property damage injury or death Read the installation operating and maintenance instructions thoroughly before installing or servicing this equipment AWARNING Install operate and maintain unit in accordance with manufacturer s instructions to avoid exposure to fuel substances or substances from incomplete combustion which can cause death or serious illness The state of California has determined that these substances may cause cancer birth defect
6. 1 Open all manual gas valves 2 Lack of power at unit 2 Replace fuse or turn on power supply Turn up thermostat Check limit switch with continuity tester If open replace limit switch Check wiring per diagrams Replace gas valve Check thermostat and replace if defective 292 Chart 6 Trouble Shooting continued SYMPTOMS POSSIBLE CAUSES CORRECTIVE ACTION Defective transformer Loose wiring Defective ignition control 10 Be sure 115 volts is supplied to the transformer primary then check for 24 volts at secondary terminal before replacing Check and tighten all wiring connections Replace E Flame lifting from burner ports Pressure regulator set too high Defective regulator Burner orifice too large Reset manifold pressure Refer to operation Replace regulator section of combination gas valve or complete valve Check with local gas supplier for proper orifice size and replace Refer to operation F Flame pops back Excessive primary air Close air shutter Refer to Operation Check with local gas supplier for proper orifice size and replace G Noisy flame Too much primary air Noisy pilot Irregular orifice causing whistle or resonance Excessive gas input a Pressure regulator set too high b Defective regulator c Burner orifice too large
7. 9 When the thermostat is satisfied the main and pilot valves close 10 The fan time delay relay remains closed keeping the fan motor operating to dissipate residual heat from the heat exchanger At this time the fan time delay relay opens and deactivates the fan motor oon 16 AIR DISTRIBUTION Two basic air control systems are used to deliver conditioned air to the occupied space constant fan operation and intermittent fan operation INTERMITTENT FAN OPERATION This air control system is available on duct furnaces when the fan time delay relay is ordered optional The thermostat turns the gas on whenever the temperature drops below the thermostat setting The fan time delay relay allows the unit to fire for a period of 60 seconds before fan operation It also allows the fan to operate for 120 seconds after burner shutdown CONSTANT FAN OPERATION Duct Furnaces This air control system is standard on duct furnaces without a fan time delay relay The blower operates constantly circulating air through the unit through the discharge continuously into the occupied zone and back to the return The thermostat turns the gas valve on or off raising the temperature of the air to maintain comfort conditions in the occupied area AIR THROUGHPUT Static Pressure through the duct furnace should not exceed 2 0 inches 0 50 kPa water column The standard outdoor duct furnaces are operated at a temperature rise range of 2
8. above sea level Check all local codes Special orifices are required for installations above 2000 ft 610 m Check all local codes In Canada if a unit is to be installed at altitudes of 2000 ft 610 m to 4500 ft 1372 m the unit must be orificed to 90 of the normal altitude rating Unless otherwise specified the following conversions may be used for calculating SI unit measurements 1 inch 25 4 mm 1000 Btu Cu Ft 37 5 MJ m 1 foot 0 305 m 1000 Btu per hour 0 293 kW 1 gallon 3 785 L 1 inch water column 0 249 kPa 1 pound 0 435 kg liter second CFM x 0 472 1 psig 6 894 FPM 196 8 1 cubic foot 0 028 m x m Figure 1 Standard Natural Vented Outdoor Duct Furnace SPECIFICATIONS 1 25 26 Typ IT 660 C Typ Vent Cap i x Is Shipped Q In Separate Carton D Y 1 H j 1 1 8 29 19 Typ Duct 483 Opening G Connection 991 realen e 10 1 8 onnections s 257 XH 5 1 16 en g
9. may result in minor injury or property damage NOTICE Used to notify of special instructions on installation operation or maintenance which are important to equipment but not related to personal injury hazards SERVICE ACCESS PANEL REMOVAL To remove an access panel door use the following procedure remove the two screws and two washers from the louvered flue discharge area of the service panel power vent doors only Each panel is held in place with two Grip Latches Using a slotted head screw driver turn the latch screwhead counter clockwise Using the handle provided pull the panel upwards Pull the bottom of the panel out and lower the panel to disengage it from the top lip To replace an access door panel guide the panel door upwards on the tracks and push up into the top lip swing and lower the panel in place until it engages with the bottom panel Turn the screwhead on each latch clockwise The screw must turn freely one quarter turn before resistance is felt in order for the lock to engage If the latch does not hold turn the screw counter clockwise several turns and repeat the above procedure Also refer to Figures 8Aa 8b and 8c for more specifications RECEIVING INSTRUCTIONS Inspect shipment immediately when received to determine if any damage has occurred to the carton crate during shipment After the unit has been uncrated check for any visible damage to the unit On power vented units check
10. o 10 250 t 08 200 ag 150 8 04 100 TUE 02 50 0 0 0 60 130 5 t F 40 4120 F 20 16 0 2000 4000 6000 8000 12000 4000 16000 Airflow CFM o BYPASS SIZING INFORMATION BUILT ON THE JOB NOT FURNISHED BY FACTORY On occassion when a duct furnace is incorporated in an air handling system it may be desirable to handle a total of more CFM than the duct furnace will pass at a given static pressure drop and temperature rise There fore it is necessary to arrange to bypass the additional CFM required The size of the bypass duct can be determined by referring to the chart This permits the static pressure drop through the bypass to balance off the drop through the heat exchanger The bypass duct is not factory furnished and must be built on the job by the installer and a damper placed therin if required Figure 5 By Pass Curve USE OF BYPASS CURVES The width of the by pass for CFM in excess of that provided through the heater may be found in the following manner 1 Determine the CFM and pressure drop through the heater based on the heating requirement specifications 2 Determine the additional CFM desired over and above the CFM for the heating requirements 3 Using the pressure drop which was determined from performance curves above for the heating load locate this pressure drop on the by pass curves Follow this curve until it intersect
11. 1 2 1 2 281 302 58 6 46 9 1 165 3 496 11 33 0 50 356 127 137 250H 250 000 200 000 80 3 086 9 259 20 60 2 22 1 4 3 4 1 2 3 4 306 327 u 73 2 58 6 1 457 4 370 11 83 0 50 565 139 148 300H 300 000 240 000 80 3 704 11 111 20 60 2 34 3 4 1 2 OR 3 4 362 384 2 87 8 70 3 1 748 5 244 11 33 0 50 864 164 174 350H 350 000 280 000 80 4 321 12 963 20 60 2 33 1 4 3 4 1 2 3 4 387 409 102 5 82 0 2 040 6 119 11 33 0 50 845 176 186 400H 400 000 320 000 80 4 938 14 815 20 60 2 38 3 4 3 4 1 2 3 4 423 455 117 1 93 7 2 331 6 993 11 33 0 50 984 192 206 100H 100 000 80 000 80 1 235 3 704 20 60 2 7 1 8 1 2 1 2 197 216 29 3 23 4 0 583 1 748 11 33 0 50 181 89 98 150 150 000 120 000 80 1 852 5 556 20 60 2 11 1 4 1 2 1 2 221 240 43 9 35 1 0 874 2 622 11 33 0 50 286 100 109 200H 200 000 160 000 80 2 469 7 407 20 60 2 14 1 2 1 2 268 289 58 6 46 9 1 165 3 496 11 33 0 50 356 122 131 250H 250 000 200 000 80 3 086 9 269 20 60 2 22 1 4 3 4 1 2 3 4 293 314 m 73 2 58 6 1 457 4 375 11 83 0 50 565 133 142 5 300H 300 000 240 000 80 3 704 11 111 20 60 2 34 3 4 1 2 3 4 340 362 a 87 8 70 3 1 748 5 244 11 33 0 50 864 154 164 350H 350 000 280 000 80 4 321 12 963 20 60 2 33 1 4 3 4 1 2 3 4 365 387 102 5 82 0 2 0
12. attached in a manner that prevents leaks GAS CONNECTIONS All gas piping should be installed in accordance with local codes It is required that a ground union be installed adjacent to the manifold for easy servicing On vertical runs a drip leg should be provided upstream of the control manifold see figure 9a An additional shut off must be located externally of the jacket enclosure where required by local code The location of this valve must comply with the local codes A 1 8 inch N P T plugged tapping accessible for test gauge connection must be installed immediately upstream of the gas supply connection to the unit Field gas piping recommendations are shown in Figure 9b It is recommended that the gas piping not be installed through the bottom of the duct furnace bottom panel If piping must penetrate the duct furnace bottom panel it must be sealed to prevent water leakage A WARNING To avoid equipment damage or possible personal injury do not connect gas pipingtothis unituntil a supply line pressure leak test has been completed Connecting the unit before completing the pressure leak test may damage the unit gas valve and result in a fire hazard CAUTION Do not rely on a shutoff valve to isolate the unit while conducting gas pressure leak tests These valves may not be completely shut off exposing the unit gas valve to excessive pressure and damage Do not overtighten the inlet gas piping Thi
13. from combustible material and from the venting cap top of unit Clearances around the outside air hood must be unobstructed A WARNING Provide adequate clearance from combustibles to prevent injury or death from fire Figure 6 Minimum Clearances to Combustible Material or Obstructions 18 457 5 16 8 Typ Power Vent Units required 36 clearance above top of unit I 18 5 16 457 8 i1 8 Natural 7 Ductwork or Power Vent Air Flow 2 se E 4 Clearance 36 914 36 914 HR 18 457 For Drawer Pul out ME D3589 See figures 1 amp 2 and charts 1 amp 2 Be VENTING venting installations shall be in accordance with the latest edition of Part 7 Venting of Equipment of the National Fuel Gas Code ANSI Z223 1 1999 or applicable provisions of local building codes Natural venting models are equipped with a vent cap designed for natural venting Air for combustion enters atthe base of the vent through a protective grille and the design of the vent cap is such that the products of combustion are discharged at the upper section of the cap The cap is shipped in a separate carton It s
14. ft 100 CFH 6 56 m F A HEATER S 150 CFH GAS METER D3588 cad d Chart 3 GAS PIPE SIZE Maximum Capacity of Pipe in Cubic Feet of Gas per Hour for Gas Pressures of 0 5 psig 3 5 kPa or Less and a Pressure Drop of 0 5 Inch Water Column 124 4 Pa Nominal Based on a 0 60 Specific Gravity Gas Iron Internal Pipe Size Dia Length of Pipe ft Meters in in 10 20 30 40 50 60 70 80 90 100 125 150 175 200 mm 3 0 6 1 9 1 12 2 15 2 18 3 21 3 24 4 27 4 30 5 38 1 45 7 53 3 61 0 1 2 0 622 175 120 97 82 73 66 61 57 53 50 44 40 37 35 16 4 96 3 40 2 75 2 32 2 07 1 87 1 73 1 61 1 50 1 42 1 25 1 13 1 05 0 99 3 4 0 824 360 250 200 170 151 138 125 118 110 103 93 84 77 72 21 10 2 7 08 5 66 4 81 4 28 3 91 3 54 3 34 3 11 2 92 2 63 2 38 2 18 2 04 1 1 049 680 465 375 320 285 260 240 220 205 195 175 160 145 135 27 19 3 13 2 10 6 9 06 8 07 7 36 6 80 6 23 5 80 5 52 4 96 4 53 4 11 3 82 11 4 1 380 1400 950 770 660 580 530 490 460 430 400 360 325 300 280 35 39 6 26 9 21 8 18 7 16 4 15 0 13 9 13 0 12 2 11 3 10 2 9 20 8 50 7 93 11 2 1 610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430 41 59 5 41 3 33 4 28 0 25 5 22 9 21 2 19 5 18 4 17 6 15 6 14 2 13 0 12 2 2 2 067 3950 2750 2200 1900 1680 1520 1400 1300 1220 1150 102
15. heater Drain connections are provided to dispose of this condensate from the unit Connect drain pipes to dispose of this condensate where necessary Ducts which are outdoors must be insulated and sealed to prevent water from entering either furnace or building through duct see section on duct and drain specifications Ducts connected to duct furnaces shall have removable access panels on both upstream and downstream sides of the unit These openings shall be accessible when the unit is installed in service and shall be of such size that smoke or reflected light may be observed inside the casing to indicate the presence of leaks in the heating element The covers for the openings shall be attached in such a manner as to prevent leaks If a duct furnace is connected to a return air duct or any other inlet air restriction the appliance shall be installed on the positive pressure side of the air circulating blower Atmospheres containing solvents or chlorinated hydrocarbons will produce corrosive acids when coming in contact with the flames This will greatly reduce the life of the gas duct furnace and may void the warranty Avoid such areas CLEARANCES Minimum clearances are shown in Figures 1 2 amp 6 and charts 1 amp 2 It is important that clearances be main tained for servicing the unit refer to Figures 1 amp 2 for clearances necessary to pull out the burner drawer for servicing and that minimum clearances are provided
16. motor position and turn blower wheel by hand to determine if damage has occurred to these critical parts If any damage is found the consignee should sign the bill of lading indicating such damage and immediately file claim for damage with the transportation company PRE INSTALLATION INSTRUCTIONS When unit is received and uncrated check data plate on unit for type of gas and electrical specifications and make certain that these agree with those at point of installation A WARNING Open all disconnect switches and secure in that position before installing the unit Failure to do so may result in personal injury or death from electrical shock NOTICE It is the equipment owner s responsibility to provide any scaffolding or other apparatus required to perform emergency service or annual periodic maintenance to this equipment RIGGING Rig the unit using either belt or cable slings Use spreader to protect the top of the unit when it is lifted The furnace units are provided with two holes in the base rail on each side of the unit Slide pipes beneath the unit through these holes and attach rigging to the pipes for lifting the unit LOCATION Before placing the rooftop unit in its permanent location make certain that the roof is capable of carrying the additional load of this equipment Check the shipping weights given in Chart 2 Refer to Figures 1 2 and 6 and charts 1 and 2 for adequate unit dimensions and requir
17. refer to local codes or in absence of local codes refer to the National Fuel Gas Code ANSI Standard Z223 1999 N F P A no 54 or the latest edition When installed in Canada any references to deration at altitudes in excess of 2000 feet 610m are to be ignored At altitudes of 2000 to 4500 feet 610 to 1372m the unit heaters must be orificed to 90 of the normalaltitude rating and be so marked in accordance with the CSA certification NOTICE There may be momentary and spasmodic orange flashes in the flame This is caused by the burning of airborne dust particles and not to be confused with the yellow tipping which is a stable or permanent situation when there is insufficient primary air PRIMARY AIR SHUTTER ADJUSTMENT After the unit has been operated for at least 15 minutes adjust the primary air flow to the burners Turn the friction locked manually rotated air shutters clockwise to close or counterclockwise to open For correct air adjustment close the air shutter until yellow tips in the flame appear Then open the air shutter to the point just beyond the position where yellow tipping disappears 1 With unit firing remove the pilot adjustment cap 2 Adjust the pilot screw to provide properly sized flame PILOT ADJUSTMENT 3 A proper pilot flame is a soft steady flame that envelopes 3 8 to 1 2 inch 9 5 to 12 7 mm of the flame sensor 4 Replace the pilot adjustment cap 18 GAS INPUT ADJUS
18. the burner drawer The control and piping assembly may be tied out of the way of the pull out drawer Disconnect all wiring to the unit s controls Break the union located in the discharge end of the furnace loosen the external union and swing piping clear of the bottom of the drawer same procedure as a 3 Remove the locking screws holding the burner drawer in position 4 Slide the drawer out of the furnace 5 Burners can be removed from the drawer by raising the front of the burner and pushing it against the hold in spring until the front of the burner comes out of the slot b 6 To clean or replace the main burners slide out the pullout drawer and compress the spring by moving the burner toward the manifold Slide the opposite end of the burner downward from the locating slot while retaining spring is still compressed Pull the burners upward and out 7 Remove any dirt dust or other foreign matter from the burners using a wire brush and or compressed air Ensure that all parts are unobstructed Inspect and clean pilot burner if necessary 8 Reassemble the gas duct furnace by replacing all parts in order 9 Complete the appropriate unit start up procedure as given in the Start Up section of this manual 10 Check the burner adjustment See the Primary Air Shutter Adjustment section of this manual 11 Check all gas control valves and pipe connections for leaks AWARNING Under no c
19. 0 to 60F 17 to 50C rise The furnaces are also available at a higher temperature rise range of 30 90F 17 50C NOTICE It is important that the final temperature leaving the furnace does not exceed 150 F 66 C When final air throughput adjustments are being made a quick check of the final temperature can be made by locating a thermometer approximately 6 to 12 inches 152 to 305 mm downstream from the air discharge and approximately 3 to 4 inches 76 to 102 mm from the bottom of the duct The unit should be operated at least 15 to 20 minutes before temperature readings are made A CAUTION unit should never be allowed to cycle over a prolonged period on the high limit The high limit is not an operating control It is a safety control to prevent a fire If cycling on the high limit is noted corrective measures should be taken immediately Failure to do so could cause unit damage and possible fire AIR FILTERS It is recommended that air filters be changed or cleaned at least twice a year More frequent attention will be required if the air being handled is unusually dirty Air flow reduction caused by clogging air filters will increase the discharge air temperature and may cause nuisance tripouts Filters by others should be serviced regularly and changed or washed when necessary to maintain the required throughput In a dusty environment filters may clog up in less than one month CLOGGED FILTE
20. 0 950 850 800 53 112 77 9 62 3 53 8 47 6 43 0 39 6 36 8 34 5 32 6 28 9 26 9 24 1 22 7 21 2 2 469 6300 4350 3520 3000 2650 2400 2250 2050 1950 1850 1650 1500 1370 1280 63 178 123 99 7 85 0 75 0 68 0 63 7 58 0 55 2 52 4 46 7 42 5 38 8 36 2 3 3 068 11000 7700 6250 5300 4750 4300 3900 3700 3450 3250 2950 2650 2450 2280 78 311 218 177 150 135 122 110 105 97 7 92 0 83 5 75 0 69 4 64 6 4 4 026 23000 15800 12800 10900 9700 8800 8100 7500 17200 6700 6000 5500 5000 4600 102 651 447 362 309 275 249 229 212 204 190 170 156 142 130 1 See local codes before installing 1 2 pipe 2 FOR NATURAL GAS cu ft hr Hate of Unit Btu Value of Gas 3 FOR PROPANE GAS Multiply the Cu Ft Hr obtained in note 2 by 0 633 before entering chart ELECTRICAL CONNECTIONS A WARNING HAZARDOUS VOLTAGE DISCONNECT ALL ELECTRIC POWER INCLUDING REMOTE DISCONNECTS BEFORE SERVICING Failure to disconnect power before servicing can cause severe personal injury or death The rooftop duct furnace is wired at the factory and ready to be connected Actual wiring will differ according to the options used Each furnace will be shipped with its own wiring diagram refer to this wiring diagram for all electrical connections to the unit electrical connections must conform to ANSI NFPA No 70 1999 or latest edition Nation
21. 40 6 119 11 33 0 50 845 166 176 400H 400 000 320 000 80 4 938 14 815 20 60 2 38 3 4 3 4 1 2 3 4 401 433 117 1 93 7 2 331 6 993 11 33 0 50 984 182 196 See figures 1 and 2 UP indicates low temperature rise furnace The clearances dimensions shown in chart 42 are the absolute minimum clearances for servicing the burner drawer However the clearances shown in chart 1 are the recommended clearances for ease of servicing the unit um PERFORMANCE DATA CURVES Figure 3 High Temperature Rise Duct Furnaces 30 90 F 17 50 Pressure Drop inches water Temperature Rise 0 2000 4000 6000 8000 10000 12000 Airflow Pressure drop through the heat exchanger is based on 4 Follow vertical line down to select the CFM throughput The desired data is obtained in 5 For pressure drop selection follow vertical CFM line the following manner until it intersects the selected heater performance 1 Select heater size based on heat loss of the building curve vs pressure drop to be heated 6 Follow the horizontal pressure drop line to the left 2 Select temperature rise desired and read pressure drop of the selected heater 3 Based on temperature rise the horizontal line inter sects heater temperature vs CFM curve Figure 4 Low Temperature Rise Duct Furnaces 20 60 F 11 33 m s 0 1 2 3 4 5 6 7 12
22. R SWITCH The clogged filter switch is a field installed option When the furnace air filter becomes clogged the suction increases on the downstream side of the filter causing air to be drawn through a port of the back of the clogged filter switch When suction becomes greater than the set point of the clogged filter switch it releases the red flag marked CHANGE FILTER The flag shows in clear plastic window on the front of the case The contacts make to actuate the light when the air filter needs cleaning or changing to the For adjustments and checkout refer Maintenance section of this manual LIGHTING Purge the gas line of air before attempting to light the pilot in the unit Wait 5 minutes for unburned gas to vent Check for gas leaks A WARNING Never use an open flame to detect gas leaks Explosive conditions may exist which could result in personal injury or death The unit is furnished with an intermittent pilot ignition system A lighting instruction plate is permanently attached to the unit for the pilot system supplied with the unit To set the intermittent pilot ignition system in operation proceed as follows 1 Turn on the main manual valve and pilot valve 17 LIGHTING continued 2 Turn on electrical power The unit should now be under the control of the thermostat 3 Turn the thermostat to the high heat reading to see if the pilot and main burner ignite 4 Turn the thermostat to t
23. TMENT When shipped from the factory all gas fired units are equipped for the average BTU of the gas stamped on the rating plate A CAUTION Since the BTU content of gases varies in many localities the input must be checked after installation of the unit If the unit is overfired the overheating will substantially shorten the life of the heat exchanger Never exceed the input on the rating plate The input may be checked by either the meter method or the pressure of the gas in the manifold A 1 8 inch pipe tap is available on the body of the gas valve A CAUTION Never overfire the unit heater as this may cause unsatisfactory operation or shorten the life of the heater METER METHOD OF CHECKING INPUT 1 Obtain the heating value of the gas from the local utility This should be in BTU per cubic foot MJ m 2 Determine the cubic feet per minute of the gas as shown in the following example The rating plate input should be taken from the unit as stamped on the plate EXAMPLE Assume this is a unit having an input of 250 000 BTU hr and the heating value of the gas to be used in the furnace is 1000 BTU hr 250 000 BTU hr 1000 BTU cu ft x 60 min hr 41 7 cu ft per min Before checking the unit input all other gas appliances connected to the same meter must be turned off 3 Fire the unit according to instructions 4 Observe on the meter dial the cubic feet of gas for a per
24. al Electrical Code and applicable local codes In Canada to the Canadian Electrical Code Part CSA Standard C22 1 CAUTION Do not use any tools i e screwdriver pliers etc across the terminals to check for power Use a voltmeter The outdoor conduits leading into the unit should be installed to prevent rain from wetting any high voltage wire Locate the thermostat in accordance with the instructions packed with each thermostat NOTICE Should any original wire supplied with the heater have to be replaced it must be replaced with wiring material having a temperature rating of at least 105 C 221 F 12 OPERATION GENERAL All units are equipped with intermittent pilot ignition systems This system is 10096 pilot burner shut off See Figure 11 for burner gas controls The pilot is lit and extinguished during every cycle of operation There is no burning standing pilot On natural gas units the ignitor will continue to spark and pilot gas will continue to flow until the pilot flame is proven LP propane gas units are equipped with 10096 lockout The lockout function shuts off the main and pilot gas valves if the pilot gas fails to ignite within 30 seconds In order to initiate a reignition trial the power supply must be interrupted for 30 seconds NOTICE Check gas supply pressure see chart 4 Gas valves are suitable to a maximum pressure of 0 5 psi 14 inches water column If the main ga
25. delay optional on duct furnaces is energized The fan time delay relay closes and activates the fan motor o BON NOTICE The unit firing rate is controlled by the hydraulic sensing bulb on the mechanical valve is in series with the single stage electrically operated valve 6 The Hydraulic sensing bulb on the mechanical modulating valve calls for heat 7 The mechanical modulating valve opens allowing gas flow to the main burners Main burners are lit at 40 percent of the unit s rated input The mechanical modulating valve modulates between 40 percent and 100 percent of firing rate depending on the temperature rise required 8 The unit continues to fire until the hydraulic sensing bulb is satisfied and no longer calls for heat 9 The mechanical modulating valve closes which shuts off the main gas supply to the burners 10 The room thermostat is satisfied and no longer calls for heat The main and pilot valves close At this time the fan delay relay opens and deactivates the fan motor HYDRAULIC MODULATING CONTROL WITH BYPASS Natural or propane gas units only with an additional electric valve are provided in parallel with the hydraulic modulating valve The electric valve bypasses the gas flow around the hydraulic modulating valve s sensing bulb control The electric valve is activated by a low voltage single stage thermostat 15 GAS CONTROLS continued With power applied to the unit this system operates in th
26. diately 4 Secure all exterior panels in place MAINTENANCE A WARNING Open all disconnect switches and secure in that position before servicing unit Failure to do so may result in personal injury or death from electrical shock Rooftop duct furnaces have been developed for outdoor installation Should maintenance be required perform the following inspection and service routine Inspect area near the unit to be sure that there is no combustible material located within minimum clearance requirements refer to Figures 1 2 and 6 Service panels provide easy access to the burner controls To remove the service door refer to Access Panel Removal section at the beginning of this manual The pilot burner can be serviced by removing the pilot plate from the main burner assembly To remove the main burner drawer assembly for servicing the burners proceed as follows 1 Shut off the main gas valve and electrical power to the gas duct furnace 2 To slide out the burner drawer the following two procedures a or b may be chosen depending on the complexity of the unit s controls a Disconnect the pilot burner gas tube Break the union between the automatic gas valve and the burner manifold Also break the union on the discharge air end of the furnace inside the unit Loosen the union located directly outside of the furnace s bottom panel refer to figure 9b Swing down this end of the piping to clear the bottom of
27. e following manner 1 The thermostat calls for heat NOTICE If a thermostat is not supplied steps 2 through 5 will be constantas long as power is applied to the unit 2 The pilot valve opens 3 The pilot sparks continuously to ignite the pilot 4 The sensor proves pilot ignition and shuts off the ignitor NOTICE The unit firing is controlled by the hydraulic sensing bulb on the mechanical valve The mechanically operated valve is in series with the single stage electrically operated valve 5 With the pilot lit the main electric gas valve opens At this time the fan time delay optional on duct furnaces is energized The fan time delay relay closes and activates the fan motor 6 The unit is equipped with a bypass manifold containing a single stage electric valve which is in parallel with the hydraulic modulating gas valve The bypass is activated by a thermostat and overrides the hydraulic control The override thermostat should be a remote room thermostat If the temperature falls below the override thermostat s setpoint the thermostat opens the bypass valve and the unit operates at full fire The unit will continue at full fire until the override thermostat is satisfied and no longer calls for heat at which point the bypass valve is closed The unit is again controlled by the hydraulic sensing bulb on the mechanical valve 7 The hydraulic sensing bulb on the mechanical valve calls for heat 8 The mechanical modula
28. ed clearances MOUNTING The units are mounted on skids and are suitable for use on combustible flooring It is recommended that the skids be mounted either on level solid planking or steel channels but never on a soft tar roof where the skids could sink and reduce the clearance between the bottom panel and the roof GENERAL SAFETY INFORMATION Roofcurb kits for rooftop gas heating units are shipped knocked down A curb kit contains insulated curb rails hardware sealant self adhering rubber gasketing and installation instructions Roof insulation cant strips flashing roof felts caulking and nails must be furnished by the installer See separate curb specifications from manufacturer AWARNING Failure to comply with the general safety information may result in extensive property damage severe personal injury or death A WARNING not alter the unit heater in any way or damage to the unit and or severe personal injury or death may occur A WARNING Never service any component without first disconnecting all electrical and gas supplies to the unit or severe personal injury or death may occur A CAUTION Ensure that all power sources conform to the requirements of the unit heater or damage to the unit will result Installation must be made in accordance with local codes or in absence of local codes with ANSI Standard Z223 1 1999 N F P A No 54 National Fuel Gas C
29. essive primary air Main burner ports clogged near pilot Pressure regulator set too low Pilot decreases in size when main burners come on Pilot flame too small Close air shutter Refer to operation Clean main burner ports Reset manifold pressure Refer to operation Supply piping is inadequately sized Refer to installation Clean pilot orifice Refer to operation C Pilot will not light or will not stay lit Main gas off Pilot adjustment screw turned too low on combination main gas valve Air in gas line Dirt in pilot orifice Open all manual gas valves Increase size of pilot flame Purge air from gas supply Remove pilot orifice Clean with compressed air or solvent Do not ream Thermostat not calling for heat Defective limit switch Improper thermostat or trans former wiring at gas valve Defective gas valve Defective thermostat 5 Extremely high or low gas 5 Refer to operation pressure 6 Pilot valve not opening 6 a Faulty wiring a Inspect amp correct all wiring b Defective ignition control b Replace c Defective valve c Replace 7 No spark T a Faulty wiring a Inspect amp correct all wiring b Defective pilot b Replace c Defective ignition control c Replace d Sensor grounded d Inspect amp correct ignition system D Main burners will not light 1 Main gas off
30. ge thermostat With power applied to the unit this system operates in the following manner 1 The first stage of the thermostat call for heat 2 The pilot valve opens 3 The ignitor sparks continuously to ignite the pilot 4 The sensor proves pilot ignition and shuts off the ignitor With the pilot lit the main gas valve open to low fire Main burners are lit at 40 percent of unit s rated input 7 The fan time delay relay optional allows the heat exchanger to come up to operating temperature At this time the fan time delay closes and activates the fan motor 8 Ifadditional heat is required the second stage of the thermostat calls for heat 9 The main gas valve opens to full fire The main burners are now at full fire The unit continues a full fire until the second stage of the thermostat is satisfied and no longer call for heat 10 The main valve closes to low fire The main burners are now at low fire The unit continues at low fire until the first stage of the thermostat is satisfied and no longer calls for heat 11 The main and pilot valves closes 12 The fan time delay remains closed keeping the fan operating to dissipate residual heat from the heat exchanger At this time the fan time delay relay opens and deactivates the fan motor oon HYDRAULIC MODULATING CONTROL Natural gas or propane units with hydraulic modulating control are provided with a modulating gas valve capable of firing from 40 pe
31. ge air temp high fire External static pressure fi 25 STERLING HVAC PRODUCTS 260 NORTH ELM ST WESTFIELD MA 01085 TEL 413 564 5540 FAX 413 562 5311 http www mestek com S AN MESTEK COMPANY S2
32. gnitor sparks continuously to ignite the pilot 4 The sensor proves pilot ignition and shuts off the ignitor With the pilot lit the main gas valve opens Main burners are lit at 100 percent of unit s rated input 7 The fan time delay relay optional on duct furnaces allows the heat exchanger to come up to operating temperature At this time the fan time delay relay closes and activates the fan motor 8 The unit is controlled by the electronic thermostat which modulates the unit from 100 to 40 percent of unit s rated input The electronic thermostat can be a duct thermostat or a room thermostat An amplifier receives an electrical signal from the thermostat and converts this into a working voltage This working voltage determines the position of the modulating valve With no voltage applied to the valve the valve will be full open and full fire will occur As increasing voltage is applied to the valve the valve will modulate closed At approximately 12 volts dc the valve will be at it s minimum fire position As temperature drops the voltage also drops causing the relay to reopen the valve The unit will continue to cycle in this manner until either an increase in the units firing rate is required or the thermostat is satisfied and no longer calls for heat If the voltage continues toincrease indicating a further reduction in the unit s firing is required the increased voltage closes a relay which closes the automatic gas valve
33. he lowest setting to interrupt power to the ignition system to determine that both the pilot burner and main burner are extinguished 5 Setthe thermostat at the desired setting for normal operation For complete shutdown 1 Turn the main and pilot valves to the OFF position 2 Shut off electric power 3 Adjust the thermostat to the lowest setting Figure 12 Main Burner Flames Chart 5 Main Burner Orifice Schedule TYPE OF GAS NATURAL PROPANE HEATING VALUE 1075 BTU Ft 2500 BTU Ft INPUT 40 1 MJ m 93 1 MJ m IN MANIFOLD 3 5 W C 10 W C NO OF 1000 PRESSURE 0 87kPA 2 49 kPA BURNER BTU ORIFICES FT 96 40 100 ORIFICE DRILL 42 54 FT 9 HR 120 50 125 ORIFICE DRILL 42 54 5 FT HR 140 60 150 ORIFICE DRILL 42 54 6 FT 163 70 175 ORIFICE DRILL 42 54 7 FT 186 80 200 ORIFICE DRILL 42 54 8 FT 210 90 225 ORIFICE DRILL 42 54 9 FT 233 100 250 ORIFICE DRILL 42 54 10 FT 280 120 300 ORIFICE DRILL 42 54 12 FT HR 326 140 350 ORIFICE DRILL 42 54 14 FT HR 372 160 400 ORIFICE DRILL 42 54 16 D3652 Y 079 U YA NORMAL LIFTING HARD FLAME TOO MUCH AIR XC un 2 YELLOW TIPPING MARGINAL TOO LITTLE AIR This schedule is for units operating within the U S A at normal altitudes of 2000 ft 610m or less For altitudes above 2 000 ft
34. heat exchanger Check voltage to power venter motor clean power venter wheel and heat exchanger and oil power venter motor Check filters replace if necessary 5 Adjust dampers accordingly 24 Chart 6 Trouble Shooting continued SYMPTOMS POSSIBLE CAUSES CORRECTIVE ACTION N Too much heat 1 2 Thermostat malfunction Heater runs continuously a Improper thermostat or transformer wiring at gas valve b Short circuit c Defective or sticking gas valve d Excessive gas supply pressure 1 2 Replace thermostat a Check wiring per diagrams b Check operation at valve Look for short and correct such as staples piercing thermostat wiring c Replace gas valve d Refer to operation P Power venter motor will not start gt Lack of power at unit Defective power venter relay Defective motor Thermostat not calling for heat Defective limit switch gt Replace fuse or turn on power Replace Replace Turn up thermostat Replace limit switch Q Noisy power venter Power venter wheel loose 2 Bearings dry Power venter wheel blade dirty Power venter wheel rubbing housing N Tighten or replace Oil bearings on power venter motor Clean power venter wheel blade Realign power venter wheel R Power venter will not run Loo
35. hould be fastened in position as shown in Figure 7 and should not be altered in any way A WARNING The venting is an integral part of the unit and must not be altered in the field If altered excessive carbon monoxide could be produced Figure 7 Vent Cap Assembly Natural Vented Furnaces Only D3591 FIELD INSTALLATION INSTRUCTIONS 1 Remove Side Access Panel 2 Insert Vent Sleeve of Vent Cap Assembly Item 1 thru Top Panel Assembly Item 2 and over Vent Collar of Flue Collector Assembly Item 3 Align Vent Cap Assembly so it is square to Top Panel Assembly Fasten with Drill Screw or Sheet Metal Screw Item 4 by reaching between Flue Collector Assembly Item 3 amp Top Panel Assembly Item 2 and drilling through vent sleeve of Vent Cap Assembly into vent collar of Flue Collector Assembly Replace Side Access Panel 5 NOTICE If your unit is to be equipped with the optional extended vent cap assembly see the special instructions supplied with the vent cap Power vented models are designed with combustion air inlet and flue products outlet located in the louvered side access panel Never locate these units in an area where the flue products outlet may be directed at any fresh air vents See Figures 8a 8b and 8c for installation and servicing requirements Figure 8a Power Venter Discharge Location
36. iod of five minutes This should be 41 7 cu ft per min x 5 minutes or 20 8 cu feet Minor input adjustments can be made by moving the regulator screw clockwise for increased input and counter clockwise for decreased input Any appreciable adjustment in input should be made by re orificing MANIFOLD PRESSURE METHOD OF CHECKING INPUT 1 Close the manual gas valve on the unit 2 Install a 1 8 inch pipe connection in the tapped hold provided on the valve body and a U tube or manometer by means or a rubber hose 3 Fire the unit and observe the pressure 4 Small variations in gas pressure adjustment can be made by means of the pressure regulator Remove the cap from the regulator Turning the screw clockwise will increase the input and turning it counterclockwise will decrease the input The adjusted manifold pressure should not vary more than 1096 from the pressures specified in chart 5 START UP Before starting the rooftop gas heating unit use the Installation Check Sheet found at the end of this manual in conjunction with the procedures outlined below to ensure that the unit is completely and properly installed and ready for start up 1 Inspect all wiring connections connections should be clean and tight 2 Trace circuits to ensure that actual wiring agrees with the as wired diagrams provided with the unit Information in the title block of the wiring diagram s should match the data appearing on the unit na
37. ional manner Has the gas and electric been inspected by the local authority having jurisdiction Is the gas supply properly sized for the equipment Were the installation instructions followed when the equipment was installed Have all field installed controls been installed eee ee eee ee Do you understand all the controls on this equipment DO NOT START this equipment unless you fully understand the controls GENERAL With power and gas off Make certain all packing has been removed Tighten all electrical terminals and connections Check damper linkages for tightness Check all fans amp bowers for free movement Check all controls for proper settings Check all set screws on blowers and bearings Check belt tightness Co r c cL BLOWER With power on and gas off Check voltage L1 L2 L3 Check rotation of main blower Check motor amps L1 L2 L3 Blower RPM Check air filters Record quantity amp size Qr Remarks Ql Lc Lc LL LL 5 27 GAS HEATING With power and gas on Inlet gas pressure in W C Pilot amp main burner ignition Manifold gas pressure in W C Cycle on HIGH LIMIT Cycle firestat and or freezestat Check electronic modulation Set at Check mechanical modulation Set at Cycle and check all other controls not listed Check operation of remote panel Entering air temp F F in W C Cycle by thermostat or operating control Dischar
38. iping layout of the whole installation and calculate the cubic feet of gas that each supply pipe will carry See piping example below Calculate the cubic feet of gas that each supply pipe will carry Btu Hr 1000 Btu Natural Gas Cu Ft Cu Ft Per Hour of Gas to Unit cfh Unit Kilowatt 37 3 Megajoules Natural Gas Cu Meter Liters per second on Gas to Unit I s NOTICE Contact your natural gas supplier for the Btu Cu Ft content of natural gas in your area This may be higher or lower than the nominal 1000 Btu Cu Ft used in this example Refering to the piping example in figure 10 the length of pipe from the gas meter A to the most remote heater E is 60 feet This distance should be used for all of the heaters when determining the pipe size required Based on the column marked 60 feet in chart 3 the piping for this example should be sized as follows 450 cfh is supplied from A to B requiring 1 1 4 inch pipe 200 cfh is supplied from B to C requiring NOTICE If more than one gas duct furnace is to be served by the same piping arrangement the total cu ft hr input and length of pipe must be considered NOTICE If the gas duct furnace is to be fired with LP gas consult local LP gas dealer for pipe size information Heater installation for use with propane bottled gas must be made by a qualified LP gas dealer or installer He will insure proper joint compounds are used for making pipe connections tha
39. ircumstances should combustible material be located within the clearances specified in Figure 6 Failure to provide proper clearance could result in personal injury or equipment damage from fire 12 Check the operation of the automatic gas valve by lowering the setting of the thermostat stopping the operation of the gas duct furnace The gas valve should close tightly completely extinguishing the flame on the main burners 13 Check the operation of all safety devices 14 Inspect and service the blower section of the system The outdoor unit should be thoroughly checked before the start of the heating season Check the air through put as an added precaution to stay within the specified temperature limits If the unit is used with cooling equipment periodic maintenance should be scheduled throughout the year 20 Figure 13 Natural Vent Duct Furance Figure 14 Power Vent Duct Furnace 21 Chart 6 Trouble Shooting SYMPTOMS POSSIBLE CAUSES CORRECTIVE ACTIONS A Gas odor Shut off gas supply immedi ately Blocked heat exchanger Drafts around heater Negative pressure in the build ing Blocked draft hood flue collec tor Inspect all gas piping and repair Clean heat exchanger Eliminate Drafts Refer to installation See installation Clean draft hood flue collector B Delayed ignition Exc
40. meplate 3 Verify that the system switch is in the OFF position 4 Check unit supply voltage to ensure that it is within the utilization range 5 Inspect the interior of the unit remove any debris or tools which may be present STARTING UNIT IN HEATING MODE 1 Close the unit disconnect switch s that provide current to the unit control panel High voltage is present in some areas of the control panel s with the unit disconnect switch closed Failure to exercise caution when working around energized electrical components may result in injury or death from electrical shock 2 Set the room thermostat switching subbase as indicated below a position the heating system switch at either HEAT or AUTO b set the fan switch at AUTO and c adjust the temperature control setting to some point above room temperature 3 Place the system switch in the ON position With the thermostat calling for heating unit operation is automatic 19 START UP continued FINAL CHECKOUT Run the unit sequentially through its stages of heating One proper unit operation is verified perform these final steps 1 Inspect the unit for debris and or misplaced tools and hardware 2 Disable air handling blower Fire unit and confirm that high limit switch shuts gas off within approximately 5 minutes Re enable air handling blower 3 Be sure all gas valves and controls are in the operating position if the unit will be operating imme
41. n t turn off Poor thermostat location Defective thermostat Improper thermostat or trans former Short circuit Defective or sticking gas valve Excessive gas supply pres sure Relocate thermostat away from drafts Replace thermostat Check wiring diagrams Check operation at valve Look for short and correct such as staples piercing thermostat wiring Replace gas valve Refer to operation L Rapid burner cycling Loose electrical connections at gas valve or thermostat Excessive thermostat heat anticipation Unit cycling on high limit Poor thermostat location Tighten all electrical connec tions Adjust thermostat heat antici pation for longer cycles Refer to operation Check for proper air supply across heat exchanger Relocate thermostat Do not mount thermostat on unit M Not enough heat 3 4 Incorrect gas input Heater undersized Thermostat malfuction Heater cycling on limit control Check outside dampers if used Refer to operation 2 This is especially true when the heated space is enlarged Have the heat loss calculated and compare to the heater output 79 or 80 of input see chart 2 Your gas supplier or installer can furnish this information If heater is under sized add additional heaters Replace thermostat Check air movement through
42. ode or the latest edition All of the ANSI and NFPA Standards referred to in these installation instructions are those that were applicable at the time the design of the appliance was certified The ANSI Standards are available from the American Gas Association 1515 Wilson Boulevard Arlington Virginia 22209 The NFPA Standards are available from the National Fire Protection Association Batterymarch Park Quincy MA 02269 If installed in Canada the installation must conform with local building codes or in absence of local building codes with current CGA B149 1 Installation Codes for Natural Gas Burning Appliances and Equipment or CGA B149 2 Installation Codes for Propane Gas Burning Appliances and Equipment These outdoor duct furnaces have been designed for and certified to comply with CGA 2 8 These units have been designed and certified for outdoor use only and may be located on the roof of the building or at any convenient location external of the building to be heated The input range is 100 000 BTU HR 29 3 kW to 400 000 BTU HR 117 1 kW in 50 000 BTU HR 14 6 kW increments The venting is an integral part of the unit and must not be altered in the field The Natural Vented units are equipped with a vent cap which is designed for gravity venting Air for combustion enters at the base of the vent through a protective grille and the design of the vent cap is such that the products of combustion are discharged at
43. r n id 9 Duct and Drain Specifications 10 Gas Connections 10 11 12 Electrical Connections 12 OPERATION General Information 13 14 Auto Spark 13 GODlttolS edet etta 14 Gas 14 15 16 Air Distribution Throughput 17 Lighting en 17 18 Primary air Shutter Pilot Adjustment 18 Gas Input Adjustment 19 START UP ess vce niter ege 19 20 20 21 TROUBLE SHOOTING GUIDE 22 25 REPLACEMENT PARTS 26 WARRANTY en 26 GAS EQUIPMENT CHECK SHEET 27 The following terms are used throughout this manual to bring attention to the presence of potential hazards or to important information concerning the product Indicates an imminently hazard ous situation which if not avoided will result in death serious injury or substantial property damage A WARNING Indicates an imminently hazard ous situation which if not avoided could result in death serious injury or substantial property damage CAUTION Indicates an imminently hazardous situation which if not avoided
44. rcent to 100 percent of rated input Ignition is at low fire 40 percent of input The hydraulic modulating valve is controlled by a sensing bulb located in the discharge air stream which modulates the gas input from 40 percent to 100 percent of rated input The modulating valves are available in two temperature ranges 60 100 F or 75 200 F setpoint adjustments x 3 5 are shown in the following table Dial Setpoint 11213 14 5 6 7 8 9 60 100 F 60 65 70 75 80 85 90 95 100 75 200 F 75 91 106 122 138 150 NA NA NA Maximum furnace discharge temperature allowed 150 F The unit is also provided with an automatic electric valve in series with the hydraulic modulating valve which typically cycles the unit in response to a low voltage single stage thermostat Units not utilizing a thermostat will operate as a standing pilot unit The ignitor will light the pilot and the pilot will remain on until power is disconnected from the units With power applied to the unit this system operates in the following manner 1 The thermostat calls for heat NOTICE If a thermostat is not supplied steps 2 through 5 will be constant as long as power is applied to the unit The pilot valve opens The ignitor sparks continuously to ignite the pilot The sensor proves ignition and shuts off the ignitor With the pilot lit the main electric gas valve opens At this time the fan time
45. s or other reproductive harm INSTALLER S RESPONSIBILITY Installer Please Note This equipment has been test fired and inspected It has been shipped free from defects from our factory However during shipment and installation problems such as loose wires leaks or loose fasteners may occur It is the installer s responsibility to inspect and correct any problems that may be found These units are certified by CSA International for operation on either natural or propane gas Read this manual and all labels attached to the unit carefully before attempting to install operate or service the following unit models Outdoor Rooftop Duct Furnaces QV RT PV 100 150 200 250 300 350 400 H M RT Natural Vent PV Power Vent Look in the direction of the unit air flow to determine whether the unit is right or left hand accessible 455 STERLING HVAC PRODUCTS 260 NORTH ELM ST WESTFIELD MA 01085 TEL 413 564 5540 FAX 413 562 5311 http www mestek com MESTEK COMPANY TABLE OF CONTENTS RECEIVING PRE INSTALLATION 2 GENERAL SAFETY INFORMATION 2 3 SPECIFICATIONS Dimensional Data 4 5 Performance and Specification Data 5 Performance Data Curves 6 7 INSTALLATION Location Mounting 2 3 8 Clearances iicet 4 5 8 Venlting in
46. s supply pressure for natural gas is greater than 14 inches WC 3 5 kPa a stepdown pressure regulator must be installed ahead of the gas valve For LP propane gas the gas pressure supplied should not exceed 14 inches WC 3 5 kPa The controls are located inside the compartment on the access side of the unit The input for single stage firing is based on full fire On two stage fire the unit will fire 4096 of full fire on the first stage and full fire on the second stage When hydraulic modulating is used the unit will first fire at 4096 of full fire and modulate up to full fire When electronic modulating is used the unit will first fire at 100 of full fire and modulate down to 40 of full fire Figure 11 Burner Components Intermittent Pilot Ignition Natural or Power Vented Duct Furnaces BURNER DRAWER COMMON PARTS MAIN BURNERS BURNER MANIFOLD AIR SHUTTERS BURNER SPRINGS MAIN BURNER ORIFICE TRANSFORMER PILOT TUBING CONTROLS 8A MAIN GAS VALVE HONEYWELL 8B MAIN GAS VALVE WHITE RODGERS 9 HONEYWELL IGNITOR 10 HONEYWELL PILOT BURNER OPERATION Chart 4 Gas Supply Pressure continued Natural Gas Propane Gas Heating Value 1075 Btu Ft 2500 Btu Ft 40 1 MJ m 93 1 MJ m Manifold Pressure 3 5 in W C 10 0 in W C 0 87 kPa 2 49 kPa Minimum Supply Pres
47. s may cause stresses that would crack the valve A WARNING Never use an open flame to detect gas leaks Explosive conditions may exist which would result in personal injury or death The gas line should be supported so that no strain is placed on the unit Pipe compounds which are not soluble to liquid petroleum gases should be used on threaded joints The appliance and its individual shutoff valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressure in excess of 1 2 psig 3 5 kPa The appliance must be isolated from the gas supply piping system by closing its individual manual shutoff valve during any pressure testing of the gas supply piping system at test pressure equal to or less than 1 2 psig 3 5 kPa For additional piping information refer to National Fuel Gas Code ANSI 7233 1 1999 or latest edition Figure 9a Drip Leg Installation TO GAS LINE ALTERNATE TO GAS LINE C TO GAS CONTROLS c3 1 Il c4 3 In Min DRIP LEG 76mm Min D3587 Figure 9b Field Piping Recommendations NIPPLE ELBOW NIPPLE UNION NIPPLE 3 ELBOW NIPPLE UNION D3726 10 GAS CONNECTIONS continued For the most satisfactory piping installation the following procedure should be followed Make p
48. s thevertical CFM line for the excess CFM desired 4 Follow horizontal line to left to obtain width of by pass duct 12 WA WIDTH OF BY PASS DUCT INCHES IHHHHHHE 0 0 1 000 2 000 3 000 6 000 4 000 5 000 7 000 C F M THRU BY PASS INSTALLATION A WARNING Open all disconnect switches and secure in that position before installing unit Failure to do so may result in personal injury or death from electrical shock Installation must conform with local building codes or in the absence of local codes with the National Fuel Gas Code ANSI Z223 1 1999 or the latest edition A heat loss study and a complete layout of the system should be made first When locating the unit in its permanent location make certain that the roof is capable of carrying the additional load of the equipment Check the net weights from the engineering data Make certain that clearances are provided for service minimum clearance to combustible material and to venting cap See below for this information Service clearance information is given in the engineering data in Figures 1 2 and 6 Clearances around secondary air must be unobstructed If the unit is installed downstream of refrigeration coils condensate will form and collect in the bottom of the
49. se wiring Defective motor overload protector or defective motor Defective power venter relay Check and tighten all wiring connections per diagrams Replace motor Check for 24V across 1 amp 3 terminals on fan relay If 24V is present jumper terminals numbered 2 and 4 If motor runs relay is defective and must be replaced If 24V is not present check wiring diagrams S Power venter motor will not stop 1 2 Improperly wired fan relay Defective fan relay N Check all wiring Replace fan relay Indicates Power Vent Units Only 25 How to order Replacement Parts Please provide the following information to your local representative Models Number Serial Number if any Part Description and Number as shown in Replacement Parts Literature If further assistance is needed please contact the manufacturer s customer service department SERVICE NOTE organization incur a problem the nature of which is not Due to the many configurations options and voltage herein we urge you to contact manufacturer It would characteristics available on Outdoor Duct Furnaces be of great assistance to use if you can provide the the information provided in their manual is somewhat model and serial number and wiring diagram number general in its context Should user or service as well as access type LIMITED WARRANTY Gas Fired Engineered Products Natural or Po
50. sure Single Stage Application 5 0 in W C 11 0 in W C 1 24 kPa 2 74 kPa Two Stage Application 6 5 in W C 11 5 in W C 1 62 kPa 2 86 kPa CONTROLS Electronic modulating gas firing is available from the factory on natural and propane gas units Do not use a thermostatic fan control switch when either two stage firing or modulated gas controls are used A fan time delay switch can be used however and is available as an option on outdoor duct furnaces All controls are located on the access side of the unit reference Figure 11 Chart 5 lists orifice sizes for outdoor duct furnaces OPERATING HIGH LIMIT CONTROL The operating limit control is a factory installed component surface mounted in the inlet air stream end of the heat exchanger This surface mounted safety device must have adequate contact to the rear header plate of the heat exchanger to insure its function When the temperature reaches the limit set point all heat is shutoff The limit control has a built in auto reset that comes on when the equipment is sufficiently cooled down Reference the unit s wiring diagram PILOT CONTROL Intermittent pilot ignition is standard on all outdoor unit sizes Intermittent pilot ignition contains a solid state ignition control system that ignites the pilot by spark for each cycle of operation When the pilot flame is proven the main burner valve opens to allow gas flow to the burners Both the pilot and burners are exting
51. t 129 EL s 5 8 16 Typ B Anchor Hole n Opening T 4 102 Location 522 1 3 16 en Typ DFR3538A nchor Hole TFR3779A F u K Location Chart 1 Dimensional Data CAPACITY US CANADA GAS INLET CA A B D D F K NAT LP 10 32 7 8 15 9 16 12 11 20 11 16 19 3 8 30 3 16 1 2 1 2 835 395 305 279 525 492 767 15 32 7 8 18 5 16 21 1 2 16 25 3 16 23 1 2 30 3 16 1 2 1 2 835 465 546 406 640 597 767 20 43 7 8 23 13 16 23 1 2 16 25 3 16 26 1 4 41 3 16 1 2 1 2 1114 605 597 406 640 667 1046 25 43 7 8 29 5 16 23 1 2 16 25 3 16 34 1 2 41 3 16 3 4 1 2 OR 3 4 1114 745 b97 406 640 876 1046 30 54 7 8 34 13 16 26 17 1 2 26 11 16 37 1 4 52 3 16 3 4 1 2 OR 3 4 1394 884 660 445 678 946 1326 35 54 7 8 40 5 16 26 17 1 2 26 11 16 45 1 2 52 3 16 3 4 1 2 3 4 1394 1024 660 445 678 1156 1326 40 60 3 8 45 13 16 26 17 1 2 26 11 16 51 57 11 16 3 4 1 2 OR 3 4 1534 1164 660 445 678 1295 1465 NOTE DIMENSIONS ARE IN INCHES DIMENSIONS IN PARENTHESIS ARE IN MILLIMETERS EF DIMENSION IS THE RECOMMENDED CLEARANCE TO SERVICE THE BURNER DRAWER S REFER TO FIGURE 6 FOR ADDITIONAL CLEARANCE REQUIREMENTS Figure 2 Standard Power Vented Outdoor Duct Furnace 1 25 ES 26 z A Typ 660 1 Flue Product Outlet 1 1 8 29 19 ER Duct 483 ombustion ange i Air Inlet Gas Opening 39 Connection 991 Electrical
52. t air is purged from lines that a thorough test is made for leaks before operating heater and that it is properly connected to propane gas supply system Before any connection is made to an existing line supplying other gas appliances contact the local gas company to make certain that the existing line is of adequate size to handle the combined load Check all connections with a soap solution before leaving job HYDRONIC MODULATING GAS CONTROL OPTIONAL On units equipped with hydraulic modulating gas control the temperature sensing bulb for the gas valve must be field installed in the supply ductwork Carefully uncoil the capillary tubing to prevent kinking or sharp bends 1 inch pipe 250 cfh is supplied from B to D requiring A CAUTION Do not bend the capillary tubing within 1 inch pipe 1 2 12 7 mm of its connection to the bulb or the 100 cfh is supplied from D to E requiring valve Repeated bending may cause the tubing to leak 3 4 inch pipe or break 150 cfh is supplied from D to F requiring 1 inch pipe For SI calulations refer to metric conversion chart in general safety section of this manual Center and fasten the temperature sensing bulb in the supply ductwork at least one foot downstream of the furnace section Figure 10 Example of Piping Layout for Determining Pipe Size HEATER S 200 CFH 5ft 1 64 m 20 ft 6 56 m 3 48 m D HEATER S 20
53. termination in the reasonable opinion of the Manufacturer that there exists a defect in material or workmanship Repair or replacement of any part under this Limited Warranty shall not extend the duration of the warranty with respect to such repaired or replaced part beyond the stated warranty period THIS LIMITED WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EITHER EXPRESS OR IMPLIED AND ALL SUCH OTHER WARRANTIES INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED AND EXCLUDED FROM THIS LIMITED WARRANTY IN NO EVENT SHALL THE MANUFACTURER BE LIABLE IN ANY WAY FOR ANY CONSEQUENTIAL SPECIAL OR INCIDENTAL DAMAGES OF ANY NATURE WHATSOEVER OR FOR ANY AMOUNTS IN EXCESS OF THE SELLING PRICE OF THE PRODUCT OR ANY PARTS THEREOF FOUND TO BE DEFECTIVE THIS LIMITED WARRANTY GIVES THE ORIGINAL OWNER OF THE PRODUCT SPECIFIC LEGAL RIGHTS YOU MAY ALSO HAVE OTHER RIGHTS WHICH MAY VARY BY EACH JURISDICTION 26 GAS EQUIPMENT START UP Customer Job Name amp Number PRE INSPECTION INFORMATION With power and gas off Type of Equip Rooftop Model Number Name Plate Amperage Serial Number Name Plate Voltage LP Are all panels doors vent caps in place Type of Gas Natural Tank Capacity lbs Rating BTU F Has the unit suffered any external damage Damage Does the gas piping and electric wiring appear to be installed in a profess
54. the upper section of the cap This cap is shipped in a separate carton It should be fastened in position as shown in Figure 7 and should not be altered in any way The Power Vented unit has a power venting system with the inlet and discharge grille located in the upper section of the side access panel This balanced flue design also performs well under all wind conditions All internal parts of the standard unit are fabricated from aluminized steel Standard burners are pressed aluminized steel and have a stainless steel burner port protector and air shutters All internal and external jacket parts are fabricated from galvanized steel Stainless steel heat exchangers burners and flue collectors are optional An optional 321 or 409 stainless steel heat exchanger is highly recommended for the following applications 1 When the entering air temperature is below 40 F 4 4 C 2 When the furnace is installed downstream of a cooling coil section A pilot burner plate is provided for access to the pilot burner and ignition systems without removing the burner drawer Clearances between the external unit and obstruction must be sufficient for proper servicing of pull out drawer See Figures 1 and 2 for this clearance The outdoor units are certified for operation on either natural or propane gas If a unit is to be installed at an altitude exceeding 2000 ft 610 m above sea level derate the input by 4 for each 1000 foot rise 305 m rise
55. ting valve opens allowing gas flow to the main burners Main burners are lit at 40 percent of the unit s rated input The mechanical modulating valve modulates between 40 percent and 100 percent of firing rate depending on the temperature rise required 9 The unit continues to fire until the hydraulic sensing bulb is satisfied and no longer calls for heat 10 The mechanical modulating valve closes shutting off the main gas supply to the burners 11 The room thermostat is satisfied and no longer calls for heat The main and pilot valves close At this time the fan delay relay opens and deactivates the fan motor ELECTRONIC MODULATING CONTROL Units with electronic modulating control are provided with an electronic modulating valve capable of firing from 100 percent to 40 percent of rated input Ignition is at full fire 100 percent of unit s rated input The electronic modulating valve is controlled by a room thermostat or duct thermostat with remote setpoint adjustment which modulates the gas input from 100 percent to 40 percent of rated input An optional override room thermostat is available for use with the duct thermostat The override room thermostat allows full fire and overrides the duct thermostat when the room temperature falls below the override room thermostat s setpoint With power applied to the unit this system operates in the following manner 1 The thermostat calls for heat 2 The pilot valve opens 3 The i
56. uished during the off cycle HIGH GAS LINE PRESSURE REGULATOR Natural Gas only The pressure regulator is a field installed component located external of the unit and as close as possible to where the gas line inlet enters the unit The pressure regulator reduces the main gas line pressure to a minimum of seven inches W C 1 74 kPa GAS CONTROLS SINGLE STAGE CONTROL Gas heating units are factory provided with an automatic single stage gas valve This valve is an on off type control typically activated by a low voltage single stage thermostat 1 The thermostat calls for heat 2 The pilot valve opens 3 The ignitor sparks continuously to ignite the pilot 4 The sensor proves pilot ignition and shuts off the ignitor 5 With the pilot lit the main gas valve opens 6 Main burners are lit at 100 percent of unit s rated input 7 The fan time delay relay optional allows the heat exchanger to come up to operating temperature At this time the fan time delay relay closes and activates the fan controls 8 The unit continues to fire until the thermostat is satisfied and no longer calls for heat 9 The main and pilot valves close 14 GAS CONTROLS continued TWO STAGE CONTROL Optional two stage control is provided with a two stage gas valve capable of firing at 100 and 40 of rated input Ignition at a low fire 4096 of the unit s rated input and the unit is typically controlled by a voltage two sta
57. wer Vented Outdoor Duct Furnaces The Manufacturer warrants to the original owner at the original installation site that the Gas Fired Engineered Products the Product will be free from defects in material or workmanship for a period not to exceed one 1 year from the date start up or eighteen 18 months from the date of shipment from the factory whichever occurs first If upon examination by the Manufacturer the Product is shown to have a defect in material or workmanship during the warranty period the Manufacturer will repair or replace at its option that part of the Product which is shown to be defective This limited warranty does not apply a if the Product has been subjected to misuse or neglect has been accidentally or intentionally damaged has not been installed maintained or operated in accordance with the furnished written instructions or has been altered or modified in any way b to any expenses including labor or material incurred during removal or reinstallation of the defective Product or parts thereof c to any damage due to corrosion by chemicals including halogenated hydrocarbons precipitated in the air d to any workmanship of the installer of the Product This limited warranty is conditional upon a shipment to the Manufacturer of that part of the Product thought to be defective Goods can only be returned with prior written approval from the Manufacturer All returns must be freight prepaid b de
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