In all instances, other than wiring for the thermostat, the wiring to be done and any replacement of wire shall conform with the temperature limitation for Type T wire
Connect a sufficiently sized wire with ground to the furnace’s line voltage connections and ground lug. Refer to the furnace rating plate for electrical characteristics to be used in sizing field supply wiring and overcurrent protection.
The line voltage supply should be routed through a readily accessible disconnect located within sight of the furnace. A junction box on the furnace side panel is provided for line voltage connections. Refer to the furnace wiring diagram for specific connection information.
Proper polarity of the supply connections (“HOT” and “NEUTRAL”) must be observed to ensure that safety controls provide the protection intended.
A connection to the ground lug and actual earth ground (typically a ground stake or buried steel pipe) must be maintained for proper operation.
Thermostat
Install a room thermostat according to the instructions furnished with it. Select a location on an inside wall that is not subject to drafts, direct sunshine, or other heat sources. The initial heat anticipator setting should be equal to the total current draw of the control circuit. Low voltage thermostat connections are to be made to the integrated ignition/blower control board as indicated on the wiring diagram.
Single Stage Thermostat Operation (A80UH2V and 80G1UH2V Models )
The automatic heat staging option allows a single stage thermostat to be used with two stage furnace models (A80UH2V or 80G1UH2V). To activate this option, move the jumper pin (see Figure 31) to desired setting (5 minutes or 10 minutes). The furnace will start on 1st stage heat and stay at 1st stage heat for the duration of the selected time before switching to 2nd stage heat.
W1 on the control board must be connected to W1 on the thermostat.
Humidifier
Terminals are provided on the integrated ignition/blower control board for connection to a
Automatic Heat Staging Jumper
Figure 31
Electronic Air Cleaner
Terminals are provided on the integrated ignition/blower control board for connection of a
Variable Speed Features
This furnace is equipped with a variable speed circulation air blower motor that will deliver a constant airflow within a wide range of external static pressures. Other features of this variable speed motor include:
Soft Start
The variable speed motor will slowly ramp up to normal operating speed. This minimizes noise and increases comfort by eliminating the initial blasts of air encountered with standard motors.
Soft Stop
At the end of a cooling or heating cycle, the variable speed motor will slowly ramp down after a short blower “off” delay. If continuous blower operation has been selected, the variable speed motor will slowly ramp down until it reaches the airflow for that mode.
Passive and Active Dehumidification
Passive Dehumidification
For situations where humidity control is a problem, a dehumidification feature has been built into the variable speed motor. At the start of each cooling cycle, the variable speed motor will run at 82% of the rated airflow for 7.5 minutes. After 7.5 minutes has elapsed, the motor will increase to 100% of the rated airflow.
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