Results from Service Visit


  #1  
Old 11-07-05, 05:42 PM
safko2000
Visiting Guest
Posts: n/a
Results from Service Visit

I had posted earlier how our Carrier condenser unit kept tripping the circuit breaker. Here's how the service call went:

a. Visual inspection of capacitor. No visible swelling or burn marks so I guess he assumed it was okay.
b. Use ohmeter to check compressor windings. No short between windings and ground
c. Used clamp on ampmeter to check current draw from compressor. Meter started at 0....when contactor applied high voltage meter went to 40+ amps and breaker tripped.
d. Disconnected compressor from circuit by removing wires from run capacitor and contactor. Reset breaker and energized contactor....fan starts to run indicating contactor, capacitor, and fan motor are all good.

Conclusion: Even though compressor windings checked okay the tech concluded that internal mechanical components (I think he called it a lock step rotor) had "frozen." I guess this rotor moves a piston which accomplished the compression action. This lock up action caused the compressor to "work harder" and draw enough amperage to trip the breaker.

And the fun part....well, see my earlier post on "Labor Charges"
 
  #2  
Old 11-07-05, 08:10 PM
S
Member
Join Date: Nov 2005
Posts: 216
Upvotes: 0
Received 0 Upvotes on 0 Posts
Did the breaker trip almost instantly when power was applied.

Compressor pull alot of amps when the start, some upwards of 90, but as soon as they start pumping the go down.

If the breaker was tripping before the compressor ever got started might try a new breaker first and see.

I had one that was tripping the breaker, and the breaker wouldn't trip for a good few seconds
 
  #3  
Old 11-08-05, 03:52 AM
safko2000
Visiting Guest
Posts: n/a
The circuit breaker is rated at 60 amps which the technician thought was a bit high. I watched the meter clipped around the compressor wire off the contactor and it started at zero amps, then went quickly to over 40 amps in about 2 seconds after high voltage was applied. At that point the breaker tripped. You might have something there because I really didn't hear anything from the compressor as far as trying to start up. Guess I'll go over to the Home Depot and get a new breaker. Thanks
 
  #4  
Old 11-08-05, 04:15 AM
mattison's Avatar
Member
Join Date: Mar 2003
Location: Cinti, OH
Posts: 5,315
Upvotes: 0
Received 0 Upvotes on 0 Posts
Look at the plate rating on the condensor. Somewhere on there it will say Max Breaker or Max Circuit Protection.

Like said, on start up you could potentially have double the amps for a few seconds, then they will level out. Normally if a compressor is locked up it will take out the internal safety 1st.
 
  #5  
Old 11-08-05, 04:44 AM
safko2000
Visiting Guest
Posts: n/a
Information plate says max breaker is 60 which is the size currently in the panel. I wished I would have watched the meter a bit closer but don't recall it going that high on the current draw before th breaker tripped. Well..for
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: