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# 47860A005

Page 22

OPERATION

Sequence of Operation

Heating

During a call for heat the thermostat closes the R-W
circuit of the control board.  The control board verifies limit
switches are closed and pressure switch is open. The
induced draft blower relay closes causing the blower to
run. As vent pressure is developed by the induced draft
blower, the pressure switch closes. After a 15-second pre-
purge, the control energizes the hot surface ignitor. After
the 7-second warmup time, the control energizes the main
gas valve causing the main burners to ignite. The hot
surface ignitor is de-energized 3 seconds after the main
valve opens. If flame is sensed during this time the main
valve remains energized and the control starts the
30-second heat blower “on” delay.

As heating demand is met, the thermostat de-energizes the
R-W circuit. The control de-energizes the main valve
causing the burners to shut off. The induced draft blower

Should overheating occur or the gas supply
fail to shut off, shut off the manual gas valve
to the appliance before shutting off the
electrical supply.

  WARNING

3. Move the gas control knob to the “ON” position. Use

only your hand to turn the gas control knob; never use
tools. If the knob will not turn by hand, don’t try to
repair it; call a qualified service technician. 

Force or

attempted repair may result in a fire or explosion.

4. Replace the burner access door.

5. Turn on the electrical power to the furnace.

6. Set the room thermostat to a point above room

temperature to light the main burners. After the
burners have ignited, set the room thermostat to
desired temperature.

To Shut Down Furnace:

1. Set the room thermostat to the lowest setting.

2. Turn off all electric power to the furnace.

3. Remove burner access door.

4. Shut off the gas by moving the gas control knob to the

“OFF” position.

5. Replace the burner access door.

shuts off after a 15-second post-purge delay. The circulating
air blower will continue to operate until the user-selectable
heat blower “off” delay expires. The control return to standby
mode once the heat blower “off” delay expires.

Fan “On”

During a fan “on” call, the thermostat energizes the R-G
circuit of the control board, immediately causing the fan to
energize the COOL speed. The fan remains energized as
long as the thermostat calls for fan “on” operation.

If a call for cooling is energized during a fan “on” call, the fan
continues to operate at the COOL speed. If a call for heat is
energized during a fan “on” call, the control de-energizes the
fan immediately and begins the heat call/ignition sequence.

At the end of the fan “on” call the thermostat de-energizes
the R-G circuit of the control, causing the fan to be de-
energized immediately.

Cooling

During a call for cooling, the thermostat energizes the R-Y
circuit of the control board. After a 1-second cooling “on”
delay, the control energizes the cooling fan speed. If the fan
is already energized, it remains running and does not de-
energize for the 1-second cooling fan “on” delay.

The call for cooling has priority over continuous fan
operation while a call for heating has priority over both a
call for cooling or continuous fan. Ignition lockouts for any
reason do not affect cooling operation.

As cooling demand is met, the thermostat de-energizes
the R-Y circuit of the control board. After a 60-second
cooling “off” delay, the control de-energizes the cooling
speed fan. At the end of the cooling “off” delay period, the
control returns to the standby mode.

Controls

Following is a description of the operation of some of the
controls used in this furnace. All models use one of each
control, except as noted.

Pressure Switch

The pressure switch is a normally open switch that
monitors combustion air flow. Inadequate air flow resulting
from excessive venting system restriction or a failed
combustion blower will cause the switch to remain open.

Rollout Switch

The rollout switch is a normally closed switch that opens
when abnormal temperatures exist in the burner area.
This can be caused by a restricted heat exchanger
causing main burner flame to “roll out” into the vestibule
area or burner box. These units have two rollout switches.

Содержание CG90TB

Страница 1: ... or requirements take precedence over the general instructions in this manual IMPORTANT Do not store combustible materials including gasoline and other flammable vapors and liquids near the furnace vent pipe or warm air ducts The homeowner should be cau tioned that the furnace area must not be used as a broom closet or for any other storage purposes Such uses may result in actions that could cause...

Страница 2: ... Supply and Piping beginning on page 18 of these instructions 7 Always install furnace to operate within the furnace s intended temperature rise range with a duct system which has an external static pressure within the allow able range as specified in Temperature Rise on page 24 of these instructions See furnace rating plate 8 When a furnace is installed so that the supply ducts carry air circulat...

Страница 3: ...ormance care must be taken in choosing the location for this furnace The atmosphere in which the furnace operates must be free of contaminants such as chlorides and sulfates The furnace must be installed so that electrical compo nents are protected from water Unit must be level for proper condensate drainage Horizontal Installations Figure 1 All models are suitable for closet or utility room insta...

Страница 4: ...he horizontal position are approved for attic installations If the furnace is to be installed in an attic or other insulated space it must be kept free and clear of insulating materials To avoid property damage caused by condensate drain blockage install a field fabricated auxiliary drain pan with a separate drain line to the outside under the entire furnace and drain system Install according to l...

Страница 5: ...sed there must be no exposure to the substances listed in Item 5 3 All provisions for indoor combustion air must meet the requirements for combustion air indicated in the National Fuel Gas Code ANSI Z223 1 NFPA 54 latest edition and or any applicable local codes In Canada see CSA B149 1 Natural Gas and Propane Installation Codes latest edition 4 The following types of installation may require outd...

Страница 6: ...n through an unconditioned space 1 2 Armaflex or equivalent must be used over the pipe In extreme cold climates 3 4 Armaflex is recommended Materials All pipe fittings primer and solvent cement must conform with American National Standard Institute and theAmerican Society for Testing and Materials ANSI ASTM standards The solvent shall be free flowing and contain no lumps undissolved particles or a...

Страница 7: ...r hazard or cause property damage or where condensate vapor could cause damage or could be detrimental to the operation of regulators relief valves or other equipment See Figures 5 and 6 on pages 8 and 9 for additional information on where the horizontal vent terminal can and cannot terminate For horizontal venting in situations where clearance to floor joists is limited see Horizontal Venting Low...

Страница 8: ... r a e l C D e h t e v o b a d e t a c o l t i f f o s d e t a l i t n e v o t e c n a r a e l c l a c i t r e V e h t m o r f m c 1 6 t e e f 2 f o e c n a t s i d l a t n o z i r o h a n i h t i w l a n i m r e t l a n i m r e t e h t f o e n i l r e t n e c E t i f f o s d e t a l i t n e v n u o t e c n a r a e l C F r e n r o c e d i s t u o o t e c n a r a e l C G r e n r o c e d i s n i o t...

Страница 9: ...l C D e h t e v o b a d e t a c o l t i f f o s d e t a l i t n e v o t e c n a r a e l c l a c i t r e V e h t m o r f m c 1 6 t e e f 2 f o e c n a t s i d l a t n o z i r o h a n i h t i w l a n i m r e t l a n i m r e t e h t f o e n i l r e t n e c E t i f f o s d e t a l i t n e v n u o t e c n a r a e l C F r e n r o c e d i s t u o o t e c n a r a e l C G r e n r o c e d i s n i o t e c n ...

Страница 10: ...te as shown in Figure 7 The vent pipe on horizontal runs must slope upward away from the furnace at a minimum pitch of 1 4 per foot of run to prevent accumulation of condensate Do not cement air intake into the connector on burner box Use high temperature RTV silicone sealant so intake pipe can be removed if service is required In horizontal venting applications the vent and air intake pipe must b...

Страница 11: ...astic bag containing these Installation Instructions and the User s Information Manual This restrictor plate is to be used only in non direct vent applications Place the restrictor plate into the inlet collar insert 3 section of PVC pipe field supplied then attach a 90 elbow field sup plied to the PVC pipe in all non direct vent installations see Figures 9 and 10 Two inlet air restrictor plates ar...

Страница 12: ...h temperature RTV silicone sealant so intake pipe can be removed if service is required In horizontal venting applications the vent and air intake pipe must be installed on the same side of the house within the parameters shown in Figure 11 Horizontal Direct Vent Horizontal Venting Figure 11 3 Long Piece of 2 Diameter Pipe supplied 18 6 Drain Tee supplied Height to provide 12 clearance to average ...

Страница 13: ...ination of the flue pipe and is designed to keep objects out of the flue pipe For horizontal venting refer to Figure 13 For vertical venting refer to Figure 14 The vent pipe on horizontal runs must slope upward away from the furnace at a minimum pitch of 1 4 per foot of run to prevent accumulation of condensate Prime the trap system by slowly pouring 1 cup of water down the vent pipe On initial st...

Страница 14: ... 1 Seal any unused openings in the common venting system 2 Visually inspect the venting system for proper size and horizontal pitch as required in the National Fuel Gas Code ANSI Z223 1 NFPA 54 latest edition or the CSA B149 1 Natural Gas and Propane Installation Codes and these instructions Determine that there is no blockage or restriction leakage corrosion or other deficiencies which could caus...

Страница 15: ...t the draining will occur Install the plastic pipe plug opposite of the drain Using 3 4 PVC pipe make a connection from the adapter just installed to extend just outside the unit Install a 3 4 PVC tee as shown in Figure 17 From the tee install the drain to the disposal area The top of the tee must be left open for proper condensate drainage Horizontal Installation Right to Left Airflow Furnace mus...

Страница 16: ...PT plug installed on flue pan to one side of the internal trap assembly as shown in Figure 23 2 Connect the 1 2 NPT plug supplied to the opposite side of the internal trap assembly from the plug installed in Step 1 3 Insert trap assembly supplied into flue pan see Figure 24 4 Connect a length of 3 4 PVC pipe 3 minimum to the trap assembly see Figure 25 4 Connect a length of 3 4 PVC pipe 3 minimum ...

Страница 17: ...ting condensate drain installation Pressure Switch Connection Upflow Installation The unit is shipped from the manufacturer with a black hose connected to the pressure switch The other end of Figure 25 Completing Condensate Drain Installation 3 4 Tee 3 8 Vinyl Hose supplied Be sure to avoid double trapping the vinyl hose Hose must be installed as shown the hose must be connected to the flue pan se...

Страница 18: ... return air excessive condensation will occur within the furnace CAUTION Horizontal Installation The unit is shipped from the manufacturer with a black hose connected to the pressure switch The other end of the hose must be connected to the external drain trap Route hose through gas line access hole in cabinet Then connect to 1 4 barbed fitting on drain trap assembly For right to left airflow inst...

Страница 19: ...ter leak detection has been completed Failure to follow the safety warnings exactly could result in serious injury death or prop erty damage Never test for gas leaks with an open flame Use a commercially available soap solution made specifically for the detection of leaks to check all connections A fire or explosion may result causing property damage personal injury or loss of life WARNING FIRE OR...

Страница 20: ...s wired for a higher speed the increased amp draw could cause the board control to fail and void the warranty Humidifier Terminals are provided on the blower control board for connection to a 120 volt humidifier The HUM terminal is energized whenever the thermostat calls for heat Refer to furnace wiring diagram for specific connection information Electronic Air Cleaner Terminals are provided on th...

Страница 21: ...vice which automatically lights the burners Do not try to light the burners by hand Before operating smell all around the appliance area for gas Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor What to do if you smell gas Do not try to light any appliances Extinguish any open flame Do not touch any electric switch do not use any phone in your bui...

Страница 22: ...lectable heat blower off delay expires The control return to standby mode once the heat blower off delay expires Fan On During a fan on call the thermostat energizes the R G circuit of the control board immediately causing the fan to energize the COOL speed The fan remains energized as long as the thermostat calls for fan on operation If a call for cooling is energized during a fan on call the fan...

Страница 23: ...the blower control board 4 The remaining speed taps must be connected to dummy terminals marked PARK on the blower control board Checking and Adjusting Gas Input The minimum permissible gas supply pressure for the purpose of input adjustment is 5 W C for natural gas and 11 W C for propane gas This furnace requires conversion for use with propane see Accessories section on page 26 for correct kit T...

Страница 24: ...y proper operation after servicing WARNING ELECTRICAL SHOCK FIRE OR EXPLOSION HAZARD and Table 4 Typical manifold set point for installations at altitudes from 0 to 4500 feet above sea level is 10 0 W C Temperature Rise Check the temperature rise and if necessary adjust blower speed to maintain temperature rise within the range shown on the unit rating plate High Altitude In both the United States...

Страница 25: ... control continuously monitors its own operation and the operation of the system If a failure occurs the LED will indicate the failure code The flash codes are presented in Table 5 Fault Code History Button The control stores the last five fault codes in memory A pushbutton switch is located on the control see Figure 35 on page 27 When the pushbutton switch is pressed and released the control flas...

Страница 26: ...mbly Blower wheel Blower motor Blower motor mount Blower motor capacitor Burner Group Gas manifold Main burner orifices Main burners Accessories ALPKT572 Natural Gas to Propane Conversion Kit G1D91BT and CG90TB ALPKT574 Natural Gas to Propane Conversion Kit G1D93BT AFILTHA7 Single Side Filter Frame Kit AFILT524 Side Return Filter Kit AFILT529 Bottom Return Filter Kit ANGKT557 Propane to Natural Ga...

Страница 27: ... 47860A005 Page 27 Figure 35 Connection Diagram P N 45198 006 ...

Страница 28: ... 47860A005 Page 28 Figure 36 Schematic Diagram P N 45198 006 ...

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