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507276-04B

Page 41 of 56

Issue 1904

Electrical

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

Electrostatic discharge can affect electronic components. 

Take precautions during furnace installation and service 

to protect the furnace’s electronic controls. Precautions 

will  help  to  avoid  control  exposure  to  electrostatic 

discharge  by  putting  the  furnace,  the  control  and  the 

technician at the same electrostatic potential. Neutralize 

electrostatic charge by touching hand and all tools on 

an  unpainted  unit  surface,  such  as  the  gas  valve  or 

blower deck, before performing any service procedure.

 CAUTION

Figure 63. 

Figure 64. 

The unit is equipped with a field makeup box. The makeup 

box  may  be  moved  to  the  right  side  of  the  furnace  to 

facilitate  installation.  Seal  unused  openings  on  left  side 

with plugs removed from right side. Secure the excess wire 

to the existing harness to protect it from damage.

Refer  to  Figure  66  for  field  wiring  and  Figure  67  for 

schematic wiring diagram and troubleshooting.

The  power  supply  wiring  must  meet  Class  I  restrictions. 

Protected by either a fuse or circuit breaker, select circuit 

protection and wire size according to unit nameplate.

NOTE: 

Unit  nameplate  states  maximum  current  draw. 

Maximum Over-Current Protection allowed is 15 AMP.

Holes are on both sides of the furnace cabinet to facilitate 

wiring.

Install a separate (properly sized) disconnect switch near 

the furnace so that power can be turned off for servicing.

Before connecting the thermostat check to make sure the 

wires will be long enough for servicing at a later date. Make 

sure that thermostat wire is long enough to facilitate future 

removal of blower for service.

Complete the wiring connections to the equipment. Use the 

provided unit wiring diagram and the field wiring diagram 

shown in Figure 66. Use 18 gauge wire or larger that is 

suitable for Class II rating for thermostat connections.

Electrically  ground  the  unit  according  to  local  codes  or, 

in  the  absence  of  local  codes,  according  to  the  current 

National Electric Code (ANSI/HFPA No. 70) for the USA 

and current Canadian Electric Code Part 1 (CSA standard 

C22.1) for Canada. A green ground wire is provided in the 

field makeup box.

NOTE: 

The  gas  furnace  contains  electronic  components 

that are polarity sensitive. Make sure that the furnace is 

wired correctly and is properly grounded.

Accessory Terminals

One  line  voltage  “ACC”  1/4”  spade  terminal  is  provided 

on the furnace control board. Any accessory rated up to 

one amp can be connected to this terminal with the neutral 

leg of the circuit being connected to one of the provided 

neutral  terminals.  If  an  accessory  rated  at  greater  than 

one amp is connected to this terminal, it is necessary to 

use  an  external  relay.  See  Figure  68  for  control  board 

configuration. This terminal is energized when the indoor 

blower is operating. 

One  line  voltage  “HUM”  1/4”  spade  terminal  is  provided 

on  the  furnace  control  board. Any  humidifier  rated  up  to 

one amp can be connected to this terminal with the neutral 

leg of the circuit being connected to one of the provided 

neutral  terminals.  If  a  humidifier  rated  at  greater  than 

one amp is connected to this terminal, it is necessary to 

Summary of Contents for BG951UHE

Page 1: ...personal injury or loss of life Installation and service must be performed by a licensed professional installer or equivalent service agency or the gas supplier WARNING As with any mechanical equipment personal injury can result from contact with sharp sheet metal edges Be careful when you handle this equipment CAUTION Table of Contents Unit Dimensions 2 Parts Arrangement 3 Gas Furnace 4 Shipping ...

Page 2: ...e return air with optional RAB Return Air Base 3 Bottom return air 4 Return air from both sides 5 Bottom and one side return air See Blower Performance Tables for additional information 2 Optional External Side Return Air Filter kit is not for use with optional Return Air Base Consider sizing requirements for optional IAQ equipment before cutting side return opening FRONT VIEW SIDE VIEW Unit Dimen...

Page 3: ...507276 04B Page 3 of 56 Issue 1904 Figure 1 Parts Arrangement ...

Page 4: ... 2 diameter debris screen 1 3 4 Threaded street elbow NOTE The required bellows grommet is field provided See the Gas Piping section for relevant diagrams Check equipment for shipping damage If you find any damage immediately contact the last carrier Please refer to specification sheets for available accessories Safety Information DANGER OF EXPLOSION There are circumstances in which odorant used w...

Page 5: ...operation of either the heating or the cooling unit unless it is in the full HEAT or COOL setting When installed this furnace must be electrically grounded according to local codes In addition in the United States installation must conform with the current National Electric Code ANSI NFPA No 70 The National Electric Code ANSI NFPA No 70 is available from the following address National Fire Protect...

Page 6: ...nace combustion air opening with clothing boxes doors etc Air is needed for proper combustion and safe unit operation When the furnace is installed in an attic or other insulated space keep insulation away from the furnace When the furnace is installed in an unconditioned space consider provisions required to prevent freezing of condensate drain system NOTE The Commonwealth of Massachusetts stipul...

Page 7: ...nfined space Unconfined Space An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet 1 42 m per 1 000 Btu 29 kW per hour of the combined input rating of all appliances installed in that space This space also includes adjacent rooms which are not separated by a door Though an area may appear to be unconfined it might be necessary to bring ...

Page 8: ...hey shall be of the same cross sectional area as the free area of the openings to which they connect The minimum dimension of rectangular air ducts shall be no less than 3 inches 75 mm In calculating free area the blocking effect of louvers grilles or screens must be considered If the design and free area of protective covering is not known for calculating the size opening required it may be assum...

Page 9: ...Crawl Space and Outlet Air to Outside Shipping Bolt Removal Units with 1 2 hp 3 4 hp blower motor are equipped with three flexible legs and one rigid leg The rigid leg is equipped with a shipping bolt and a flat white plastic washer rather than the rubber mounting grommet used with a flexible mounting leg See Figure 11 The bolt and washer must be removed before the furnace is placed into operation...

Page 10: ...nected to or from other heating devices such as a fireplace or stove etc Fire explosion carbon monoxide poisoning personal injury and or property damage could result WARNING Figure 13 Installation Clearances Upflow Applications Top Bottom Floor Left Side Right Side Top Plenum 1 in 25 mm Front 0 Back 0 Sides 0 Vent 0 Floor 0 Front clearance in alcove installation must be 24 in 610 mm Maintain a min...

Page 11: ...panel to facilitate installation Markings are provided on both sides of the furnace cabinet for installations that require side return air Cut the furnace cabinet at the maximum dimensions shown on Page 2 Furnace applications which include side return air and a condensate trap installed on the same side of the cabinet trap can be installed remotely within 5 ft require either a return air base or f...

Page 12: ...610 mm Maintain a minimum of 24 in 610 mm for front service access An 8 service clearance must be maintained below the unit to provide for servicing of the condensate trap For installations on a combustible floor do not install the furnace directly on carpeting tile or other combustible materials other than wood flooring Top Plenum 1 in 25 mm Front 0 Back 0 Sides 0 Vent 0 Floor 0 Front clearance i...

Page 13: ...16 Filters This unit is not equipped with a filter or rack Afield provided filter is required for the unit to operate properly Table 1 lists recommended filter sizes A filter must be in place whenever the unit is operating Furnace Cabinet Width Filter Size Side Return Bottom Return 17 1 2 16 x 25 x 1 1 16 x 25 x 1 1 21 20 x 25 x 1 1 Table 1 Duct System Use industry approved standards to size and i...

Page 14: ...o either PVC or CPVC Low temperature solvent cement is recommended during cooler weather Metal or plastic strapping may be used for vent pipe hangers Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket Canadian Applications Only Pipe fittings primer and solvent cement used to...

Page 15: ...e to the connector if desired Use a drill or self tapping screw to make a pilot hole DANGER OF EXPLOSION Fumes from PVC glue may ignite during system check Allow fumes to dissipate for at least 5 minutes before placing unit into operation DANGER 1 Measure and cut vent pipe to desired length 2 Debur and chamfer end of pipe removing any ridges or rough edges If end is not chamfered edge of pipe may ...

Page 16: ...g system are not in operation WARNING 1 Seal any unused openings in the common venting system 2 Inspect the venting system for proper size and horizontal pitch Determine that there is no blockage restriction leakage corrosion or other deficiencies which could cause an unsafe condition 3 Close all building doors and windows and all doors between the space in which the appliances remaining connected...

Page 17: ...sure and must be completely sealed to prevent leakage of combustion products into the living space CAUTION Vent Piping Guidelines This gas furnace can be installed as either a Non Direct Vent or a Direct Vent gas central furnace NOTE In non Direct Vent installations combustion air is taken from indoors and flue gases are discharged outdoors In Direct Vent installations combustion air is taken from...

Page 18: ... 10 ft plus 1 elbow Any approved termination may be added to the minimum length listed This gas furnace must have 3 to 2 reducing elbow supplied or field replacement Canadian kit installed directly Table 4 045 070 090 110 Standard or Concentric See Table 3 Intake or Exhaust 2 2 1 2 or 3 Furnace capacity 1 Which termination 2 Which needs most elbows 3 How many 4 Desired pipe size 5 What is the alti...

Page 19: ...97 97 78 78 9 36 21 70 55 23 92 92 73 73 10 31 16 65 50 18 87 87 68 68 Standard Termination at Elevation 4 501 10 000 ft Number of 90 Elbows Used 2nd Pipe 2 1 2 Pipe 3 Pipe Capacity Capacity Capacity 045 070 090 110 045 070 090 110 045 070 090 110 1 76 61 39 n a 110 95 63 38 132 132 113 113 2 71 56 34 105 90 58 33 127 127 108 108 3 66 51 29 100 85 53 28 122 122 103 103 4 61 46 24 95 80 48 23 117 1...

Page 20: ...24 81 81 74 74 9 28 13 60 45 19 76 76 69 69 10 23 8 55 40 14 71 71 64 64 Concentric Termination Elevation 4501 10 000 ft Number of 90 Elbows Used 2nd Pipe 2 1 2 Pipe 3 Pipe Capacity Capacity Capacity 045 070 090 110 045 070 090 110 045 070 090 110 1 68 53 37 n a 100 85 59 34 116 116 109 109 2 63 48 32 95 80 54 29 111 111 104 104 3 58 43 27 90 75 49 24 106 106 99 99 4 53 38 22 85 70 44 19 101 101 9...

Page 21: ... 73 72 53 53 10 21 6 50 50 28 68 67 48 48 Standard Termination Elevation 4 501 10 000 ft Number of 90 Elbows Used 2 Pipe 2 1 2 Pipe 3 Pipe Capacity Capacity Capacity 045 070 090 110 045 070 090 110 045 070 090 110 1 66 51 29 n a 95 95 73 38 113 112 93 93 2 61 46 24 90 90 68 33 108 107 88 88 3 56 41 19 85 85 63 28 103 102 83 83 4 51 36 14 80 80 58 23 98 97 78 78 5 46 31 9 85 85 53 18 93 92 73 73 6 ...

Page 22: ...507276 04B Page 22 of 56 Issue 1904 Figure 25 Figure 26 ...

Page 23: ... be followed Follow the next two steps when installing the unit in Direct Vent applications where combustion air is taken from outdoors and flue gases are discharged outdoors The provided air intake screen must not be used in direct vent applications outdoors 1 Use transition solvent cement or a sheet metal screw to secure the intake pipe to the inlet air connector 2 Route piping to outside of str...

Page 24: ...ent length must not exceed those listed in If 3 diameter pipe is used reduce to 2 diameter pipe at the termination point to accommodate the debris screen 3 Use a sheet metal screw to secure the intake pipe to the connector if desired If this unit is being installed in an application with combustion air coming in from a space serviced by an exhaust fan power exhaust fan or other device which may cr...

Page 25: ...tion care must be taken to maintain protective coatings over building materials prolonged exposure to exhaust condensate can destroy protective coatings It is recommended that the exhaust outlet not be located within 6 feet 1 8 m of a condensing unit because the condensate can damage the painted coating NOTE See Table 6 for maximum allowed exhaust pipe length without insulation in unconditioned sp...

Page 26: ... A N A 10 10 16 16 1 Refer to 99 Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook 2 Poly Propylene vent pipe PP by Duravent and Centrotherm NOTE Maximum uninsulated vent lengths listed may include the termination vent pipe exterior to the structure and cannot exceed 5 linear feet or the maximum allowable intake or exhaust vent length listed in Ta...

Page 27: ... Clearance under veranda porch deck or balcony 12 Equal to or greater than soffit depth 3 feet 9m 12 3 feet 9m within a height 15 feet 4 5m above the meter regulator assembly 3 feet 9m 6 inches 152mm for appliances 10 000 Btuh 3kw 12 inches 305mm for appliances 10 000 Btuh 3kw and 100 000 Btuh 30kw 36 inches 9m for appliances 100 000 Btuh 30kw 3 feet 9m above if within 10 feet 3m horizontally 6 fe...

Page 28: ...ches 152mm for appliances 10 000 pliances 10 000 Btuh 3kw and 50 000 pliances 50 000 Btuh 15kw 6 inches 152mm for appliances 10 000 Btuh 3kw 12 inches 305mm for appliances 10 000 Btuh 3kw and 100 000 Btuh 30kw 36 inches 9m for appliances 100 000 Btuh 30kw 3 feet 9m above if within 10 feet 3m horizontally 6 feet 1 8m 7 feet 2 1m 12 inches 305mm 1 In accordance with the current ANSI Z223 1 NFPA 54 N...

Page 29: ...re Figure 38 2 Intake and exhaust pipes should be placed as close together as possible at termination end refer to illustrations Minimum separation is 3 76 mm on roof terminations and 6 152 mm on sidewall terminations 3 On roof terminations the intake piping should terminate straight down using two 90 elbows see Figure 36 4 Exhaust piping must terminate straight out or up as shown A reducer may be...

Page 30: ...rance above grade or average snow accumulation B Horizontal separation between intake and exhaust C Minimum from end of exhaust to inlet of intake D Exhaust pipe length E Wall support distance from top of each pipe intake exhaust 12 305 mm Min 12 305 mm Min 6 152 mm Min 24 610 mm Max 9 227 mm Min 12 305 mm Min 16 405 mm Max 6 152 mm Max 6 152 mm Min 24 610 mm Max 9 227 mm Min 12 305 mm Min 20 508 ...

Page 31: ...piping may be equipped with a 90 elbow turndown Using turndown will add 5 feet 1 5 m to the equivalent length of the pipe 8 A multiple furnace installation may use a group of up to four terminations assembled together horizontally as shown in Figure 41 Figure 40 Figure 41 Figure 42 Figure 43 Figure 44 Direct Vent Application Using Existing Chimney 3 8 76MM 203MM STRAIGHT CUT OR ANGLE CUT IN DIRECT...

Page 32: ... SNOW ACCUMULATION SIZE PER EXHAUST PIPE TERMINATION SIZE REDUCTION TABLE Figure 46 Non Direct Vent Field Supplied Wall Termination SIZE TERMINATION PER EXHAUST PIPE TERMINATION SIZE REDUCTION TABLE 3 If exhaust piping must be run up a sidewall to position above snow accumulation or other obstructions piping must be supported every 24 610 mm as shown in Figure 47 When exhaust piping must be run up...

Page 33: ...Termination Drain Trap assembled Figure 49 Kit 51W18 USA 15Z70 Canada Parts Identification and Assembly Exhaust from Furnace To Termination Exhaust from Furnace To Termination Kit 51W18 is shown Figure 50 Crawl Space Vent Pipe Drain Trap Assembled Incorrectly Figure 51 Upflow or Downflow Furnace with Exhaust through Crawl Space KIT 51W18 USA Basement Floor To Termination 1 2 PVC to Code Approved D...

Page 34: ...ee Figure 57 and Figure 58 Upflow furnace Figure 53 In upflow furnace applications the field provided vent must be a minimum 1 to a maximum 2 length above the condensate drain outlet connection Any length above 2 may result in a flooded heat exchanger if the combined primary drain line were to become restricted Horizontal furnace Figure 55 In horizontal furnace applications the field provided vent...

Page 35: ...ing from furnace must slope down a minimum of 1 4 per ft toward trap Figure 54 Condensate Trap with Optional Overflow Switch When combining the furnace and evaporator coil drains together the A C condensate drain outlet must be vented to relieve pressure in order for the furnace pressure switch to operate properly WARNING ...

Page 36: ...ce must slope down a minimum of 1 4 per ft toward trap Figure 56 Unit with Cooling Coil Using Separate Drain Figure 57 Evaporator Coil Using a Common Drain Figure 58 Evaporator Coil Using a Common Drain Piping from furnace and evaporator coil must slope down a minimum 1 4 per ft toward trap ...

Page 37: ...507276 04B Page 37 of 56 Issue 1904 Figure 59 Trap Drain Assembly Using 1 2 PVC or 3 4 PVC ...

Page 38: ...sing suitable hangers or straps Install a drip leg in vertical pipe runs to serve as a trap for sediment or condensate 5 A 1 8 N P T plugged tap or pressure post is located on the gas valve to facilitate test gauge connection See Figure 60 6 In some localities codes may require installation of a manual main shut off valve and union furnished by installer external to the unit Union must be of the g...

Page 39: ...507276 04B Page 39 of 56 Issue 1904 Figure 61 Gas Piping Upflow Applications Figure 62 Gas Piping Horizontal Applications ...

Page 40: ...0 16 42 530 15 01 490 13 87 460 13 03 430 12 18 400 11 33 1 1 2 38 1 1 610 40 894 2100 59 46 460 41 34 1180 33 41 990 28 03 900 25 48 810 22 94 750 21 24 690 19 54 650 18 41 620 17 56 2 50 8 2 067 52 502 3950 111 85 2750 77 87 2200 62 30 1900 53 80 1680 47 57 1520 43 04 1400 39 64 1300 36 81 1220 34 55 1150 32 56 2 1 2 63 5 2 469 67 713 6300 178 39 4350 123 17 3520 99 67 3000 84 95 2650 75 04 2400...

Page 41: ...tat check to make sure the wires will be long enough for servicing at a later date Make sure that thermostat wire is long enough to facilitate future removal of blower for service Complete the wiring connections to the equipment Use the provided unit wiring diagram and the field wiring diagram shown in Figure 66 Use 18 gauge wire or larger that is suitable for Class II rating for thermostat connec...

Page 42: ...t pump refer to the FM21 installation instruction or appropriate dual fuel thermostat instructions Indoor Blower Speeds 1 When the thermostat is set to FAN ON the indoor blower will run continuously on the fan speed when there is no cooling or heating demand 2 When the furnace is running in the heating mode the indoor blower will run on the heating speed 3 When there is a cooling demand the indoor...

Page 43: ...507276 04B Page 43 of 56 Issue 1904 Figure 67 Typical Wiring Diagram ...

Page 44: ...or gas Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor The gas valve on the unit is equipped with a gas control switch lever Use only your hand to move switch Never use tools If the switch will not move by hand do not try to repair it Force or attempted repair may result in a fire or explosion Placing the Furnace into Operation This furnace is e...

Page 45: ...ive minutes to clear out any gas If you then smell gas STOP Immediately call your gas supplier from a neighbor s phone Follow the gas supplier s instructions If you do not smell gas go to next step 8 Move gas valve switch to ON See Figure 69 Figure 69 9 Replace the upper access panel 10 Turn on all electrical power to the unit 11 Set the thermostat to desired setting NOTE When unit is initially st...

Page 46: ...ee Figure 69 Check gas line pressure with unit firing at maximum rate Low pressure may result in erratic operation or underfire High pressure can result in permanent damage to gas valve or overfire On multiple unit installations each unit should be checked separately with and without other units operating Supply pressure must fall within range listed in Table 11 Manifold Pressure Measurement 1 Rem...

Page 47: ...set and require no adjustment Table 12 Burner Orifice Conversion Kits at Varying Altitudes Capacity 0 7 500 ft 0 2 286m 7 501 10 000 ft 2 286 3 048 m Natural to LP Propane LP Propane to Natural High Altitude Natural Burner Orifice Kit High Altitude LP Propane Burner Orifice Kit 045 11K50 73W80 51W01 11K45 070 090 110 Conversion requires installation of a gas valve regulator spring which is provide...

Page 48: ... 2 Visually inspect the venting system for proper size and horizontal pitch Determine there is no blockage or restriction leakage corrosion or other deficiencies which could cause an unsafe condition 3 To the extent that it is practical close all building doors and windows and all doors between the space in which the appliances connected to the venting system are located and other spaces of the bu...

Page 49: ...e Figure 70 Figure 70 Constant Torque Motor These units are equipped with a constant torque ECM motor It has a DC motor coupled to an electronic control module both contained in the same motor housing The motor is programmed to provide constant torque at each of the five selectable speeds The motor has five speed taps Each tap requires 24 volts to energize Thermostat Heat Anticipation Set the heat...

Page 50: ... 920 100 0 10 1360 325 1270 255 1180 205 915 115 865 100 0 20 1310 335 1250 265 1130 215 880 120 815 110 0 30 1275 340 1205 275 1100 225 835 125 775 115 0 40 1250 355 1175 280 1065 230 795 135 730 125 0 50 1215 370 1145 295 1045 240 745 145 670 130 0 60 1200 380 1100 310 995 245 705 150 640 140 0 70 1145 380 1070 310 960 255 670 160 585 145 0 80 N A N A 1035 320 925 265 610 165 550 155 BG951UH090C...

Page 51: ...440 1745 340 1620 275 1430 195 0 10 2170 660 1920 460 1715 350 1595 290 1380 205 2160 660 1880 460 1705 345 1570 285 1380 205 0 20 2130 680 1865 475 1670 370 1560 305 1345 220 2115 680 1835 470 1670 365 1535 305 1325 220 0 30 2095 700 1835 490 1640 390 1525 325 1285 230 2060 705 1795 495 1630 380 1505 320 1285 230 0 40 2065 720 1785 510 1600 405 1465 335 1250 245 2050 720 1760 510 1570 400 1455 33...

Page 52: ...y to empty condensate water 3 Remove the clean out cap from the condensate trap and empty water Inspect the trap then reinstall the clean out cap Cleaning Heat Exchanger If cleaning the heat exchanger becomes necessary follow the below procedures and refer to Figure 1 when disassembling unit Use papers or protective covering in front of furnace while removing heat exchanger assembly 1 Turn off ele...

Page 53: ... the 2 pin plug to the wire harness 38 Reconnect drain tubes between flue collar and cold end header box 39 Secure burner assembly to vestibule panel using four existing screws Burners are self aligning to center of clam shells 40 Reconnect gas supply line to gas valve 41 Reconnect flame rollout switch wires 42 Reconnect sensor wire and reconnect 2 pin plug from ignitor 43 Reconnect wires to gas v...

Page 54: ...tly stored next to the furnace may obstruct the combustion air supply This could cause incomplete combustion and the production of carbon monoxide gas Table 13 Diagnostic Codes for 02 Control 02 Integrated Control LED Codes Red LED Flash Code Diagnostic Codes Status of Furnace LED Off No power to control or control hardware fault detected Heartbeat1 Control powered displayed during all modes of op...

Page 55: ... heat burner operation 1 Flash Reverse line voltage polarity 2 Flashes Improper earth ground 3 Flashes Burner failed to light or lost flame during heat demand 4 Flashes Low flame signal check flame sensor 5 Flashes Watchguard burner failed to light exceeded maximum number of retries or recycles 6 Flashes Not used 7 Flashes Primary or Secondary limit open or watchguard mode limit switch open longer...

Page 56: ...m height of eight 8 feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or equipment The sign shall read in print size no less than one half 1 2 inch in size GAS VENT DIRECTLY BELOW KEEP CLEAR OF ALL OBSTRUCTIONS 4 INSPECTION The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall not app...

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