Nordyne Understanding Furnace Thermostat Wiring and Thermostat Wiring Diagrams

Connecting Power Supply Wires

1.Remove the furnace control panel cover.

2.Route wires (115 VAC) through the strain relief on the left side of the furnace control box (see Figure 24).

3.Connect the hot wire to the black pigtail lead, and the neutral wire to the white pigtail lead. Secure all connections with suitable wire nuts.

4.Connect the ground wire to the grounding screw.

5.Reinstall the control panel cover and secure with the original mounting screws.

Low Voltage Wiring

The thermostat must be installed according to the instructions supplied by the thermostat manufacturer.Low voltage connections (24VAC) from the thermostat are wired to the terminal strip on the integrated control in the furnace.

NOTE: The thermostat must not be installed on an outside wall or any other location where its operation may be adversely affected by radiant heat from fi replaces, sunlight, or lighting fi xtures, and convective heat from warm air registers or electrical appliances. The nominal anticipator setting is 0.4. (Refer to the thermostat literature for additional information.)

Five-conductor thermostat wire is recommended for 24 volt low-voltage circuit (2-wire is required for furnace only; 5-wire for heating and optional cooling systems). Refer to table 6 for thermostat wire information.

Connecting Thermostat Wires

1.Insert 24 volt wires through the plastic grommet just above the control panel.

2.Connect the thermostat wires to the furnace low voltage pigtails (see Figure 25).

3.Connect low-voltage circuit to the wall thermostat.

4.A hole may be made in the furnace cabinet to ease thermostat wiring. Make sure that the wiring is protected from the sharp edge of the added hole.

On-Off	Thermostat Wires
Switch
	Furnace
Blower	Control Box
Plug	To combustion
Power	Blower or Flame
	Roll-out Switch
Entry

To Gas Valve

On-Auto Switch or Burner (Heating Models Only)

Figure 24. Control Panel (All Models)

Verifying Anticipator Setting

After the furnace is installed, check the thermostat anticipator against the nominal setting of 0.4.

1.Connect the milliamp meter in series with one of the gas valve’s low voltage terminals.

2.Energize the gas valve.

3.Read the value of the milliamps.

4.Adjust the heat anticipator of the thermostat to the value on the milliamp meter. If the heat anticipator is set too high, the furnace may delay turning on. If set too low, the furnace may cycle frequently and not provide comfort to the homeowner.

			Recommended T’STAT Wire
Thermostat			Length (Unit to T’STAT)
Wire Gauge			2-Wire	5-Wire
			(Heating)	(Heating/Cooling)
24			55	25
22			90	45
20			140	70
18			225	110
	Table 6. Thermostat Wire Gauge
Thermostat				M1/M5 A/C
				Ready Furnace
		Red		Red
	Rc
	RH
	W	White		White
	G	Green		Green
	Y	Yellow		Grey

Figure 25. Thermostat Wiring For

A/C Ready Models

Grounding

WARNING:

To minimize personal injury, the furnace cabinet must have an uninterrupted or unbroken electrical ground. The controls used in this furnace require an earth ground to operate properly. Acceptable methods include electrical wire or conduit approved for ground service. Do not use gas piping as an electrical ground!

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