SYSTEM OPERATION
AFE18-60A CONTROL BOARD
DESCRIPTION
The AFE18 control is designed for use in heat pump applica- tions where the indoor coil is located above/downstream of a gas or fossil fuel furnace. It will operate with single and two stage heat pumps and single and two stage furnaces. The AFE18 control will turn the heat pump unit off when the furnace is turned on. An
An optional outdoor thermostat,
controls, if the outdoor thermostat fails closed in this position during the heating season, it will turn on the furnace during the cooling season on a “Y” cooling demand. In this situation, the furnace produces heat and increases the indoor temperature thereby never satisfying the cooling demand. The furnace will continue to operate and can only be stopped by switching the thermostat to the off position or removing power to the unit and then replacing the outdoor thermostat. When the AFE18 receives a “Y” and “O” input from the indoor thermostat, it recognizes this as a cooling demand in the cooling mode. If the outdoor thermo- stat is stuck in the closed position switching the “Y” demand to the “W1” furnace input during the cooling mode as described above, the AFE18 won’t allow the furnace to operate. The outdoor thermostat will have to be replaced to restore the unit to normal operation.
HIGH VOLTAGE!
Disconnect ALL power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury or death.
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