Author Topic: compressor  (Read 3826 times)

Offline harrydhaines

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compressor
« on: August 09, 2007, 04:58:59 PM »
Hey,
  I am having a problem with a friends a/c unit. Everything works except for the compressor. There is correct voltage going to it. when i check there is continuity at the compressor terminals and i dont think there should be.  Can anyone help ???

Offline TECH X

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Re: compressor
« Reply #1 on: August 09, 2007, 10:23:48 PM »
You will get resistance between C and S, C and R, and R and S.
 
Disconnect the wires from the compressor.  If you measure for example, 4 between C and R, and 6 between S and C, then you must have 10 between S and R. 

(S and R = C and R + S and C) 

That would tell you the windings are fine.

If you measured infinity you have an open winding, which could just mean the overload protection has opened.

Have you tested the capacitor?  A failed capacitor could cause the compressor to overheat and go off on overload.

Zero resistance would indicate you have a short and a dead compressor winding.

I would try the capacitor first.

Good luck.  ;)

Offline ProTemp

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Re: compressor
« Reply #2 on: October 12, 2007, 02:34:04 PM »
As tech_x said...if you dont have an actual ohm reading between those wires, the the compressor overload is open or your windings are open. You might have a burn out. Those the freon smell like burnt motor windings? Thats usualy a good way of knowing...lol. Always check your windings at the compressor terminals and not the wires at the contactor or capacitor. Too many times i seen techs prematurely condeming a compressor meanwhile it was melted spades connectors at the compressor...hope this was helpful...Tech_288

Offline HVACJOE

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Re: compressor
« Reply #3 on: October 19, 2007, 10:50:41 PM »
Also, check the windings to ground, any resistance means its pooched, and as they said if it doesnt start its probably the capacitor, does it trip the breaker?