Rear Heat Pump will not turn on E7 error

[Daquenzer]

The front heat pump works fine. Rear heat pump gets E7 error code. I have reset thermostat. Does not fix problem. The circuit breaker is OK.

Suggestions?

[uncle_bob]

Hi

E7 normally means "no 120V power". What it means on this case, hopefully that's it.

The most common way to get the error is to have half of a 50A feed go down. Wiring on the pedestal breaker or socket can be the culprit. If you have a good EMS with a readout, it should let you know if this is the case.

Assuming you have power to both sides of the feed, tracking things with a multimeter is the next part of the process. Measure at the panel input and at the breaker output. Then check at the AC it's self.

If all of the power checks out, you likely have a blown control board.

Bob

[Daquenzer]

Originally Posted by uncle_bob

Hi

E7 normally means "no 120V power". What it means on this case, hopefully that's it.

The most common way to get the error is to have half of a 50A feed go down. Wiring on the pedestal breaker or socket can be the culprit. If you have a good EMS with a readout, it should let you know if this is the case.

Assuming you have power to both sides of the feed, tracking things with a multimeter is the next part of the process. Measure at the panel input and at the breaker output. Then check at the AC it's self.

If all of the power checks out, you likely have a blown control board.

Bob

So line 2 on EMS says I am not drawing any amps.

[overlander63]

50 amp systems have two breakers for the air conditioners. Likely the one you are having trouble with has tripped its breaker for some reason. Try resetting, and see if that fixes the issue.
You ARE on 50 amp service, right???

[Daquenzer]

Originally Posted by overlander63

50 amp systems have two breakers for the air conditioners. Likely the one you are having trouble with has tripped its breaker for some reason. Try resetting, and see if that fixes the issue.
You ARE on 50 amp service, right???

On 50 amp. Breaker inside is OK. My guess is since I am not drawing amps on line 2 from the pedestal based on my EMS that no power is getting to circuit. Thus the E7. Tomorrow I am going switch to 30 amp adapter and plug in the 30 amp part of pedestal and see if it works. My hunch is it will.

[uncle_bob]

Originally Posted by Daquenzer

So line 2 on EMS says I am not drawing any amps.

Hi

Does the EMS show 120V on line 2? If it's zero volts then you have a problem outside the trailer. If it's not zero volts, the problem is inside (or as mentioned above an issue with an adapter ....).

If a 50A breaker or one of the others is tripped, get it back on again. (all the way off then back on ...). If that's not it, grab a multimeter and start tracking voltage to the AC. Start from the 50A feed to the panel and work towards the AC unit.

Bob

[Daquenzer]

So this morning tried plugging into 30 amp. No power at all. Reset breaker at pedestal. Works