Xii. Gas Supply And Piping

tion. This lower blower speed enhances dehumidification of the conditioned air as it passes through the AC coil. For proper func- tion, a dehumidistat applied to this furnace must operate on 24 VAC and utilize a switch which opens on humidity rise.

To install/connect a dehumidistat:

1.Turn OFF power to furnace.

2.Secure the dehumidistat neutral wire (typically the white lead) to the screw terminal marked “DEHUM” on the furnace integrated control module.

3.Secure the dehumidistat hot wire (typically the black lead) to the screw terminal marked “R” on the furnace integrated control module.

4.Secure the dehumidistat ground wire (typically the green lead) to the ground screw on the furnace junction box. NOTE: Ground wire may not be present on all dehumidistats.

5.Turn ON power to furnace.

To enable the dehumidify function on the integrated control mod- ule:

1.Cut the jumper wire labeled “CUT FOR DEHUM” located adjacent to the DEHUM screw terminal.

Once the jumper wire is cut, the dehumidify function is enabled during a combination call for cooling (T-Stat) and dehumidification (Dehum-Stat). The yellow LED adjacent to the DEHUM screw ter- minal will be illuminated during dehumidification.

0	YL0	Y	B/C	G	R	W1		W2	DEHUM
0	YL0	Y	B/C	G	R	W1		W2	TWIN	DEHUMIDIFICATION
									TP1	DEHUMIDIFICATION
										LED (YELLOW)
0	YL0	Y	B/C	G	R	W1		W2	TP2
			R84						TP2
			R84					R191	DS7
	DS5	DS4		DS3		R85		R191	DS7
	DS5	DS4	R22	DS3


					CUT FOR		W14		3W
					CUT FOR			R128		DEHUMIDIFICATION
					DEHUM					DEHUMIDIFICATION
						R122				JUMPER WIRE
								CR35		(CUT TO ENABLE)
								CR35

FOSSIL FUEL APPLICATIONS

This furnace can be used in conjunction with a heat pump in a fossil fuel application. A fossil fuel application refers to a combined gas furnace and heat pump installation which uses an outdoor temperature sensor to determine the most cost efficient means of heating (heat pump, gas furnace, or both).

A heat pump thermostat with three stages of heat is required to properly use a two-stage furnace in conjunction with a heat pump. Refer to the fossil fuel kit installation instructions for additional thermostat requirements.

Strictly follow the wiring guidelines in the fossil fuel kit installa- tion instructions. All furnace connections must be made to the furnace two-stage integrated control module and the “FUR- NACE” terminal strip on the fossil fuel control board.

115 VOLT LINE CONNECTION OF ACCESSORIES (HUMIDIFIER AND ELECTRONIC AIR CLEANER)

WARNING

TO AVOID INJURY, ELECTRICAL SHOCK OR DEATH, DISCONNECT ELECTRICAL POWER BEFORE SERVICING OR CHANGING ANY ELECTRICAL WIRING.

The furnace’s integrated control module is equipped with line volt- age accessory terminals for controlling power to an optional field- supplied humidifier and/or electronic air cleaner.

The accessory load specifications are as follows:

Humidifier	1.0 Amp maximum at 120 VAC
Electronic Air Cleaner	1.0 Amp maximum at 120 VAC

Turn OFF power to the furnace before installing any accessories. Follow the humidifier or air cleaner manufacturers’ instructions for locating, mounting, grounding, and controlling these accessories. Accessory wiring connections are to be made through the 1/4" quick connect terminals provided on the furnace integrated control module. The humidifier and electronic air cleaner hot and neutral terminals are identified as HUM and EAC. All field wiring must conform to applicable codes. Connections should be made as shown.

12CIRCUIT CONNECTOR

INTEGRATED

CONTROL MODULE

EAC-N

HUM-N

HUM-H

EAC-H

HUMIDIFIER

ELECTRONIC

AIR CLEANER

OPTIONAL ACCESSORIES

Accessories Wiring

If it is necessary for the installer to supply additional line voltage wiring to the inside of the furnace, the wiring must conform to all local codes, and have a minimum temperature rating of 105°C. All line voltage wire splices must be made inside the furnace junction box.

The integrated control module humidifier terminals (HUM) are en- ergized with 115 volts whenever the induced draft blower is ener- gized. The integrated control module electronic air cleaner termi- nals (EAC) are energized with 115 volts whenever the circulator blower is energized.

24 VOLT HUMIDIFIER

A 5" long brown wire in the wire harness at the low fire pressure provides 24 VAC humidifier control. This wire is powered any time the pressure switch is closed. To connect 24 VAC HUM, connect the 24 VAC line of the humidifier to the 5” brown wire. The connec- tion can be made by either stripping the wire and using a wire nut or by using a field supplied quick connect terminal. The wiring must conform to all local and national codes. Connect the COM side of the humidifier to the B/C terminal on the furnace control board (or to the COM side of the 24 VAC transformer). Do not connect 115V humidifier to these terminals.

GENERAL

The furnace rating plate includes the approved furnace gas input rating and gas types. The furnace must be equipped to operate on the type of gas applied. This includes any conversion kits required for alternate fuels and/or high altitude.

CAUTION

TO PREVENT UNRELIABLE OPERATION OR EQUIPMENT DAMAGE, THE INLET GAS SUPPLY PRESSURE MUST BE AS SPECIFIED ON THE UNIT RATING PLATE WITH ALL OTHER HOUSEHOLD GAS FIRED APPLIANCES OPERATING.