Fan locked up and compressor hot - http://www.hvacmechanic.com/ Forums
Original message
| george88
 |  "Fan locked up and compressor hot"
, posted Mon 25 Oct 01:16  
Hi,
I have a 9-year-old Janitrol heat pump unit that quit working. The air handler was working but the breaker of the outside unit was tripped.
Yesterday morning, I switched the thermostat to "cool" and went outside to reset the breaker. The fan started with a dragging noise and the breaker tripped again within less than 20 seconds. I touched the top of the compressor, it was very hot.
Today, I switched the thermostat to "cool" and went outside to reset the breaker again. This time it tripped immediately and I could see a spark at the "contact". I tried to reset it again, and it tripped immediately but without a spark. Both times, the compressor was cold.
Trying to find out if the fan was still good. I pulled a red line, which was connected to the compressor junction box, from the relay. Thermostat was still at "off". I reset the breaker, I didn't push down the "contact" on the relay, and the fan was trying to start. The fan ran about 4, 5 seconds, stopped, then the breaker tripped with a spark at the "contact" of the relay. This time, I noticed that the top of the compressor was hot again. I reset the breaker again and it tripped immediately without a spark at the "contact" and the top of the compressor was still hot.
What does it sound like to you? Could you advise me which part might go wrong?
Thanks a lot.
George88
|
|
Replies:
|
| TexasTech
| "Re(1):Fan locked up and compressor hot" , posted Mon 25 Oct 06:23:
Your situation sounds terminal. I would check the µf of the run cap at least. 9yrs of a Janitrol is about all those units are good for. These failures are usually due to the indoor air flow being compromised by dirt or other blockage. It is easy to overcharge them in the cooling mode and when the heat mode is turned on the refrigerant pressures go sky high.
[this message was edited by TexasTech on Mon 25 Oct 06:24] |
| | george88
| "Re(2):Fan locked up and compressor hot" , posted Mon 25 Oct 10:25
Well, the thing is that I haven't turned the hearter on yet this year. The A/C just didn't work all of a sudden.
George88
|
| | Freon
| "Re(3):Fan locked up and compressor hot" , posted Tue 26 Oct 12:51
Does the condenser fan spin freely? If it does, you might have a short in the compressor windings. Normally a compressor will run for a while without the fan and then overheat. Your instant compressor heat accompanied by a blown circuit breaker seems to indicate an electrical short. Pull the disconnect to the condenser and disconnect all 3 compressor wires from the contactor being careful to write down where they go. Now put in the disconnect and see if the fan runs continuously (call for AC at the 'stat). You can measure the resistance in the compressor leads to see if there's a possible short. You'll need to identify each lead from the schematic in the unit.
Run to common = lowest reading. You are measuring the run winding only.
Start to common = medium reading. You are measuring the start winding only.
Run to start = highest reading. You are reading both windings.
(Run to common) + (Start to common) = (Run to start)
also S winding should be 3 to 6 times the value of R winding.
Example = If C to R is 1 Ohm, C to S needs to be at least 3 Ohms.
|
| | Wolfe
| "Re(4):Fan locked up and compressor hot" , posted Tue 26 Oct 19:36
Sounds like a dual value run capacitor has died. Sometimes when they go the blow their top and the terminals end up touching the side of the control compartment creating a short. Check the run cap before you go heat pump shopping.
|
|
|
|  |
|
