Copeland Internal Protector

[foglifter]

Got it, Sorry for the confusion!

[VTP99]

You failed to mention one key component.

[foglifter]

What? It's in a Heil A/C unit and there's nothing else in there. Capacitor, Starter/contactor, fan, compressor, crank heater.

The wiring is spot on with Copeland electrical guide.

[VTP99]

Are you using a TXV for a metering device ?

[foglifter]

Yes, but I don't suspect a refrigeration problem, my pressures have all been good (when running) then shuts off on protector. Wait for the protector to close and runs normally again until protector trips. The common lead is open; the compressor is not hot, the voltage in not low, the amperage is not high, the discharge is not high. How could an expansion valve cause this problem?

[VTP99]

Yes, but I don't suspect a refrigeration problem, my pressures have all been good (when running) then shuts off on protector. Wait for the protector to close and runs normally again until protector trips. The common lead is open; the compressor is not hot, the voltage in not low, the amperage is not high, the discharge is not high. How could an expansion valve cause this problem?

If it's a hard shutoff TXV your compressor will be starting against high head pressure. This would require the compressor to have a start capacitor that is typically wired to a potential relay.

[foglifter]

Ah I see your point! But I started from an evacuated system, added gas and ran, everything looking great for five minute cycles. Also, the LS and HS equalize pressures when off. For the short intervals the compressors stays running, the expansion valve is feeding and evaporator cool. Also, blew the whole system out with nitrogen, if the valve was closed the nitrogen wouldn't have blown out the low side.

[foglifter]

I think I got a dud compressor. I've only had that happen one other time, it's been several years ago, but it can happen. I guess I'm wondering if anyone else is having (or has had) problems with internal protectors on copeland hermetics.

[VTP99]

Ah I see your point! But I started from an evacuated system, added gas and ran, everything looking great for five minute cycles. Also, the LS and HS equalize pressures when off. For the short intervals the compressors stays running, the expansion valve is feeding and evaporator cool. Also, blew the whole system out with nitrogen, if the valve was closed the nitrogen wouldn't have blown out the low side.

If I remember correctly you stated that it was pulling 8amps. This to low and should be between 12+14 amps. What is the condensing unit model number ?
And yes the valve would be wide open at above 40* coil temp.