Interlocking HRV Operation to an Airhandler/Furnace Blower
When using the Interface relay contacts to initiate blower operation on a fur- nace, certain thermostats will initiate the outdoor cooling condenser when R and G are closed.
Use this wiring configuration to prevent the Interface relay contacts from initializing the condenser unit. This problem can occur at the thermostat because the Y termi- nal is connected to the G terminal internal to the stat. When R and G are closed at the furnace (by dehumidistat or relay) 24 Volts is sent to G at thermostat. 24 Volts is then sent through Y which will initiate outdoor condenser.
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