Goodman Mfg GHS8, GDS8, GMS8 Heating Heating/Cooling Room Thermostat, Volt Thermostat Wiring

WARNING

TO AVOID THE RISK OF INJURY, ELECTRICAL SHOCK OR DEATH, THE FURNACE MUST BE ELECTRICALLY GROUNDED IN ACCORDANCE WITH LOCAL CODES OR, IN THEIR ABSENCE, WITH THE LATEST EDITION OF THE NATIONAL ELECTRIC CODE.

To ensure proper unit grounding, the ground wire should run from the furnace ground screw located inside the furnace junction box all the way back to the electrical panel. NOTE: Do not use gas piping as an electrical ground. To confirm proper unit grounding, turn off the electrical power and perform the following check.

1.Measure resistance between the neutral (white) connection and one of the burners.

2.Resistance should measure 10 ohms or less.

This furnace is equipped with a blower door interlock switch which interrupts unit voltage when the blower door is opened for servicing. Do not defeat this switch.

24 VOLT THERMOSTAT WIRING

NOTE: Wire routing must not interfere with circulator blower operation, filter removal, or routine maintenance.

Low voltage connections can be made through either the right or left side panel. Thermostat wiring entrance holes are located in the blower compartment. The following figure shows connections for a “heat only” system and “heat/cool system”.

Heating		Heating/Cooling
Room Thermostat		Room Thermostat
W		W	Y
R	Y	G	R	Y	Y
	R		C	R
	C			C	C
	G			G	Remote

•Wrap the “R” leg around a clip-on amp meter 10 times.

•Energize the furnace in the heat mode.

•Record the reading.

•Divide this reading by 10.

•Set the heat anticipator on the thermostat to match this reading.

Example: If the reading on the amp meter is “4”, divide this by 10. The anticipator setting will be .4 amps.

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

WARNING

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

The furnace integrated control module is equipped with line voltage 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 in the following illustration.

Control Module

W		W	Condensing
Furnace	Furnace		Unit
Control	Control

Typical Field Wiring (24 VAC Control Circuit)

This furnace is equipped with a 40 VA transformer to facilitate use with most cooling equipment. Consult the wiring diagram, located on the blower compartment door, for further details of 115 Volt and 24 Volt wiring.

Hot 120 VAC

EAC Line Transformer

Optional { Accessories

Neutral 120 VAC

Hum Hum EAC Transformer Line

Air Cleaner

Humidifier

A single-stage thermostat with only one heating stage can be used to control this furnace.

SETTING THE HEAT ANTICIPATOR

The following method should be used in measuring the amp draw of the control circuit to assure proper adjustment of the thermostat heat anticipator

R

R

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 energized with 115 volts whenever the induced draft blower is energized. The integrated control module electronic air cleaner terminals (EAC) are energized with 115 volts whenever the circulator blower is energized.

IO-242C 16 05/05