indoor unit disconnect

[Ponchik]

You said "The indoor unit of a heat pump will turn off when the outdoor unit's disconnect is turned off." Not true for the majority of the units. You will still have indoor unit running and will still have 24 volts to the contactor coil of the outdoor unit because the control power comes from the indoor unit. The compressor will stop and you won't get any heat/cooling from the refrigerant but the indoor blower and any back up heat still function.

I will agree with you if the indoor unit has different circuit than the outdoor unit. Most of the heat pumps that I have wired have one circuits to the outdoor then wires into the indoor unit.

 

[kwired]

I will agree with you if the indoor unit has different circuit than the outdoor unit. Most of the heat pumps that I have wired have one circuits to the outdoor then wires into the indoor unit.

About the only ones I have seen this way are the "mini-split" type units. The conventional split unit type system has power supply to both units and control power comes from the indoor unit. Indoor unit can be just an air handler, air handler with electric heat, or a gas furnace and still use same outdoor unit.

Mini-splits and other similar designed units are more designed to use with more specific indoor units, conventional North American design systems are a little more generic and can be used with many indoor units.