Heat Pump Tripping Breaker - Pentair Ultratemp

[patrcarl]

Hoping someone can guide me in my troubleshooting here, as I feel like I've tried everything.

My Pentair Ultratemp single phase heat pump trips the breaker when the compressor tries to turn on. It starts up fine, fan runs through the whole 5 minute delay, then the moment the contactor for the compressor activates, it trips the breaker... too quick for it to throw any error codes. ALSO, I found that while the fan is running, electric is escaping somewhere (when bending over to look at the display panel, I put my hand on the top and thumb touched a screw on the panel and I got shocked ... then I found that the whole metal wiring casing is live). I've tried:

1. Checked all wires are fully on their locations - all look brand new and none are chewed, rotted, etc.
2. Replaced the 60a breaker at the box
3. Tested capacitor, which was fine, but replaced it anyways
4. Checked and tested compressor, wiring from panel to capacitor is fine and not corroded inside, all amperage between posts test correctly ... it's not shorted to ground.
5. I grabbed an HVAC tech working at my neighbor's house just to verify these, and he confirmed the compressor is good and not shorted to ground.
6. He confirmed all wiring looks good, checked the other components that wires are attached to, and all look great.
7. We swapped the two contactors in case the main one for the compressor was the problem, but that didn't fix it.
8. He noticed the unit wasn't grounded, and he had to run back to the other job but didn't see anywhere the electric could be escaping from...
9. So I ran brand new main lines with ground line from the breaker to the unit

Other notes:

• Label on the side says manufacture date of Nov. 2013. I know it's near the end of its 10-15 year life, but would rather fix than buy a new compressor or unit.
• The little temp sensor has been replaced twice in the last 4 years
• The compressor is quite rusted all around the bottom mounts ... could that be the place that the electric is escaping from?
• Could the refrigerant levels affect this?

Anything else I could try here? We're totally at a loss, and my kids won't swim in the pool until we get the heat working again

 

[ajw22]

Welcome to TFP.

It’s not freon.

You have an electrical short in the wiring that is the reason you are tripping the breaker and getting shocked.

Probably a chafed wire hidden someplace. Or a rat chewed a wire. Only way to find the bad wire is to disassemble theHP piece by piece so you can examine every wire. That is labor intensive and will probably require evacuating the refrigerant.

How old is the HP?

 

[patrcarl]

This heat pump was here when I bought the house 4.5 years ago, but it's probably around 8 or 9 years old - the side panel reads manufacture date of Nov 2013. Last summer I replaced everything else with some of the same components you have (IntelliFlo 011056 VSF pump, Pentair FNS Plus 60 DE Filter, and Pentair iChlor salt chlorine generator)

All wires inside the HP wiring panel seems to check out, and is all dust-free, not even spider webs. So the only other places electric goes outside of that box is up to the fan, or down to the compressor (I'll put some sheathing around these to be sure). Lines to the compressor look fine, but I could check the lines going up to the fan. Maybe other small wires to the temp sensor, etc.

Aside from the wiring going to the fan, is it possible electric is escaping out of the bottom of the compressor where it's rusted? I can't think of any other place it could be escaping from.

 

[ajw22]

No, electricity does not “escape”.

You say the HVAC Tech tested the compressor and that it is not shorted to ground.

Temp sensor wires are low voltage and not where your problem is.

You say “lines look fine”. Until you physically examine a complete wire run you cannot determine visually if there is broken insulation. It is likely under a clamp, grommet, or wire tie where you cannot see it.

You need to get an AC Tech who understands the high voltage paths in the HP to take a structured diagnostic path. Disconnect different components of the HP to isolate where the short is.

The fan runs and from what you describe the problem is in the compressor or wiring.

After 10 years it may be time for a new HP.

 

[patrcarl]

Agreed it’s on (or at) it’s last leg, but hoping to fix it for the kids and get one last horrah out of it here .

With the holiday tomorrow, I’ll check out each and every line, their hidden nooks and crannies, and hope to isolate it, and then likely end up calling a technician Tuesday.

You mentioned the problem could be in the compressor … the ohms all checked out, and it’s not shorted to ground. So, what other issues could the compressor have going on inside that could cause this?

 

[ajw22]

You mentioned the problem could be in the compressor … the ohms all checked out, and it’s not shorted to ground. So, what other issues could the compressor have going on inside that could cause this?

Dunno.

Disconnect the compressor at the contactor. If the HP runs and does not trip the CB then the electrical problem is in the compressor or the wires leading to it.

Modern compressors seem to last about 10 years.

Pentair UltraTemp Heat Pump - Further Reading

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