Conventional a/c compressor: sump heater question

[rvCharlie]

Hi,

Hoping this is the right subforum to ask this question.

Background: TraneTTX036C100A1 a/c Compressor tripped its mains circuit breaker yesterday.

Troubleshooting: After a a bit of brute force troubleshooting (disconnected all 3 compressor leads from contactor/capacitors, and disconnected one end of the outdoor fan), The unit still tripped the mains CB. Swapped the feed to my other a/c's same-size CB. Took slightly longer to trip, and I could hear a very short 'grunt' from the compressor (on the other side of the house), before the CB tripped. Walked back to the compressor, and some magic smoke had obviously been let out of something... Only thing left was the 'sump htr' circuit, which always has power available when mains supply is hot.

Temporary fix: Disconnected both leads that feed the sump heater circuit, and reconnected everything else. Compressor now runs fine.

Question: Have any of you a/c gurus ever seen a sump heater circuit fail in a dead short mode?

Extra credit: Any danger in operating the unit as-is, until I can obtain a new heater? I'm in MS (USA) and night time temps this time of year won't drop much lower than the thermostat on-point of 73 degrees.

Thanks,

Charlie

[rvCharlie]

Well, looks like I can answer my own question. Found this while searching for the part:
https://hvac-talk.com/vbb/showthread...ankcase-heater

Truly bizarre that the heater would fail shorted instead of open...

Charlie

[NiHaoMike]

The crankcase heater really is only needed during the winter for heat pump operation when the oil might otherwise get too cold. Once you get the replacement, add a diode in series to lower the power and make it last longer, possibly with a thermostat to bypass the diode on really cold days.