I have a Totaltouch stat and need a little pointer on installing a relay to control DH-BK-Y1 as discussed in the following information. The heat pump is a Trane (2h/2c)
The Totaltouch stat only opens BK (reducing the maximum CFMs when dehumidification is called for) but does not, at the same time, call for cooling unless the temp is above the cooling setpoint (there's no signal on Y/Y1 when the stat needs DH only).
Apparently you need to energize Y/Y1 at the air handler, de-energize BK for low CFMs and turn the fan on. The Totaltouch allows you to turn on the fan thru its menu when you enable dehumidification. That's good.
But I need install a relay in the air handler that simultaneously de-energizes BK and turns on Y/Y1(cooling) when the stat calls for DH.
Can someone mention the name/part/type of relay? I understand that when BOTH cooling AND DH are called for, this setup runs the fan at low CFMs until the DH setpoint is satisfied. When cooling alone is needed, the fan will run at full speed (after the Comfort-R ramp-up).