DIY Home Improvement Forum banner

Trane Heat pump capacitor exploded!

12K views 18 replies 3 participants last post by  hvactech126 
#1 ·
My 12 year old Trane XE1200 heat pump stopped working the other week, and it would trip the breaker everytime i reset the breaker.

I called in a HVAC tech from the local yellowpages, and they could not find the problem after replacing a bunch of parts (t-stat, therm, defrost board, capacitors), and did some rewiring. So i called in my friend / HVAC tech to diagnose the problem, and he was looking at the wiring at the heat pump unit. He replaced the contactor, but it would still trip the breaker. He then saw the two wires (red and black, thick) coming out of the unit (maybe the compressor or fan?) that connects to the contactor.

It is a 2 pole contactor. The black wire coming from inside the unit attaches to pole #1 on the Terminal side, and the red wire attaches to pole # 2 on the Low side.

He removed the red wire from the low side on pole # 1 of the contactor, and pressed the test button on the contactor, and the unit started! I went to feel the heat registers indoors and they were very hot (hotter than aux heat alone, so i know the heat pump was working). Thinking he somehow fixed it (by removing a wire?) we went back outside, and we noticed the motor capacitor starting to smoke, and it literally exploded. It was a tight roll of paper inside that popped out.

Now, he said he will come back next time, but does anyone know what the exact problem woudl be? Could it be a bad capacitors ? He suggested that the compressor could be the problem, but why would there still be heat when the unit was on?​
 
See less See more
#5 ·
well, you need to know what the wire went to?! if it is the black capacitor, then you need to replace it as a kit with the relay. was the wire red or purple that was removed? check your crankcase heater. They are known to have the wiring fail and short out.
Yes the capacitor is black (145-175 mfd, 330vac). What do you mean as a kit? I was planning to replace the capacitor. it was a red wire that was removed. (There is a purple wire, but that wire is already removed and tapped off from before).

I am guessing it is the CC heater since all other functions work. How do i find the specs to replaced the CC heater? Thanks for your help
 
#9 ·
ok. cc heater is on incoming side of contactor. It is powered 24/7 so you don't slog the compressor with liquid. As far as your wires to compressor go, on the compressor is the electrical box. remove this cover and ensure that the short is not in the wiring. then next thing to do is ohm the compressor windings. Also check the windings for shorts to ground. this may be best to leave to a pro. However, there are a lot of compressors that are falsely condemned. Research your contractor b4 choosing. Average life on a HP or AC is 12 - 15 in my area.
 
#10 ·
ok. cc heater is on incoming side of contactor. It is powered 24/7 so you don't slog the compressor with liquid. As far as your wires to compressor go, on the compressor is the electrical box. remove this cover and ensure that the short is not in the wiring. then next thing to do is ohm the compressor windings. Also check the windings for shorts to ground. this may be best to leave to a pro. However, there are a lot of compressors that are falsely condemned. Research your contractor b4 choosing. Average life on a HP or AC is 12 - 15 in my area.
Thank you for your responses!

Last question. If I somehow get the HP to work with only 2 of the 3 wires connected on the compressor, is it safe to leave operating?
 
#8 ·
So as it turns out, the red wire that was disconnected was actually one of the three wires for the compressor. Apparently the crank case heater was disconnected awhile ago (snipped off). I am assuming with the wire disconnected, it caused the capacitor to blow up? What is the reason for a short like this in the compressor?
 
#15 ·
cc heater is or is not hooked up? compressor could be shorted to ground. if you take one component out of the circuit one at a time you can find out what is shorted. remove the component completely out of the circuit by removing the wiring from the contactor and or capacitor. start with cc heater, then fan, then compressor. are you sure you have everything connected properly? if you have replaced the dual run capacitor (if it uses one) and you hooked the fan and compressor up backwards it could cause the compressor to pull too many amps.
 
#16 ·
cc heater is or is not hooked up? compressor could be shorted to ground. if you take one component out of the circuit one at a time you can find out what is shorted. remove the component completely out of the circuit by removing the wiring from the contactor and or capacitor. start with cc heater, then fan, then compressor. are you sure you have everything connected properly? if you have replaced the dual run capacitor (if it uses one) and you hooked the fan and compressor up backwards it could cause the compressor to pull too many amps.
The CC heater is not hooked up (already disconnected by a tech before)

I did have a few techs come out to look at the unit (and could have messed up the wiring).

Do you have a diagram of how they are basically connected? I have three capacitors: run, start + relay, and fan. There is also what looks like a sequencer. I would like to double check the connections if possible. Thanks for your help!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top