Interlocking HRV Operation to an Airhandler/Furnace Blower
When using the Interface relay contacts to initiate blower operation on a furnace, 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 terminal 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.
Wire
Connector
28
