Goodman CPLE24-1C a/c tripping breaker

[BraDolMag1]

Hello all,

As it is starting to warm up we started to run our A/C and noticed it wasn't cooling the house. The fan was blowing so I went down and checked the breaker and sure enough the two 30amp breakers for the A/C were tripped. I flipped it and it held for a second and tripped again. Multiple attempts resulted in the same outcome, it would trip within seconds. I went outside and pulled the disconnect switch, went back and flipped the breaker, and it held. So I go back outside and reinstall the disconnect switch. I hear a slight humming sound and then a little click. After returning to the basement I see that the breaker has tripped again.

One thing of interest is that all this happened with the A/C turned OFF at the thermostat. If the thermostat was set to A/C the breaker trips even faster and even sparks.

I am a first year electrical engineer student who was recently laid off from work. So needless to say I would really like to try to diagonse this issue myself for financial and knowledge reasons. Thanks in advance for any assistance guys

 

[user 4883]

Sounds like you have multiple problems here.
First; the system should not be calling for A/C with the thermostat set to OFF.
You need to see if your getting 24VAC between common and the Y terminal at the thermostat when the thermostat is shut to OFF. If so then you may have a bad thermostat and/or shorted thermostat wires.
Once you get this problem resolved, you will need to disconnect the signal wires to the contactor inside the compressor unit outside. The breaker should hold now. If not, you need to determine if it is the compressor or fan motor that is causing the problem. Obviously, to do this you will need to separate the two off the circuit. I would advise to eliminate the compressor from the circuit as you don't want to run the compressor without the fan running. If the breaker holds then you compressor is could be bad; if the breaker trips then the fan motor is could be bad. You may want to check the capacitor for the compressor and fan. This could be a dual-run capacitor or separate capacitors for each component. Replace as necessary. Before concluding that the compressor and/or fan motor is bad, you might opt to replace the breaker as it could be getting weak/touchy. Check the fan motor by spinning it by hand and see if it spins freely. This is just a preliminary check and does not rule out the fact that the motor windings could be bad. Best of Luck to You.

 

[lloyd]

Sounds like a case ground compressor. You can test this by using a meter to check for continuity between compressor terminals (after you pull the wires off) and the compressor case. Continuity between any of the terminals and the outside of the compressor means a new compressor.

 

[user 4883]

Good point Lloyd. I suspect the contactor welded closed when the compressor fried and explains why the system trips the breaker when not in A/C mode.

 

[lloyd]

Yep, I'll bet that's right