The circuit board is going bad on my heat pump and will cost too much to replace. I'm hoping to make it through the fall/winter before we replace the whole unit. I removed the black wire from the ry101 and removed the white wire from the ry102 relay and attached the black wire there. The compressor now turns on and works. Should this be ok? Or is this wired wrong? I was concerned about the capacitor. I wasn't sure if there was another circuit that controlled it or if everything was turned on through the black wire. The heater circuit that is disabled now off ry102 powered a 3,850 watt backup electric heater. The compressor pulls 2.5 amps during normal operation.

 

You're up, @#12.

 

That's some kind of special heat pump! Eight relays and a black box "drive board unit" through which the power cord magically gets to the control transformer, to run a window unit! It was only a few days ago when I posted how to run a whole house, split system air conditioner, on 3 relays (plus one for my personal fault detector circuit).

Anyway, the definition of a heat pump is that the refrigerant system is normally in heat mode. That is, the reversing valve for the Freon is not activated in the winter. It seems to me that the machine wants to turn on its low efficiency electric heater, but the T.S. has re-routed the power wires to the compressor. The compressor uses less current than the nichrome heater so there is no doubt the wiring is of sufficient size. Any parts which still work for the nichrome heater would cycle the compressor on and off, if they still work.

I see no problems with this.
Except: If the location of the machine is in a place so cold that the Freon system becomes ineffective. At that point, the nichrome heater would be necessary to get any heat out of the machine. In that case, either leave the machine as it was, using the nichrome heater, or be prepared to heat with other machines, like a baseboard heater.

 

Thank You! That is exactly the problem. On those really cold weeks ill switch the wires around like you mentioned. I'll look into your post about ruining the unit on just a few relays also. Don't see why it needs so much stuff just to turn a compressor on or off.

 

I'll look into your post about ruining the unit on just a few relays also.

I posted my design for a cool only with nichrome heat. Without the auto-defrost, a heat pump is barely more complicated than straight cool. A heat pump gets more complicated because of the defrost function. There are several ways to do the defrost function, usually dependent on a temperature sensor on the outdoor coil, and then it needs a timed sequence or another temperature sensor.

ps, please don't ruin it.