AC compressor no continuity on C


  #1  
Old 12-31-19, 12:48 AM
R
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AC compressor no continuity on C

Hi

I have a Highly AC compressor that suddenly stopped working. the compressor does have continuity between R and S but no connection to C. This means the windings themselves are ok, but the connection from the windings to the C terminal is faulty.

The terminal looks identical to this one:


Maybe the wire is off just beneath the terminal.
I realized that you can actually buy new terminal blocks, like here:
Hermetic Home Air Conditioner Terminal | Fridge Compressor Terminal | South Source Core

So my question is, (how) can the terminal block be removed from the unit?


thx & regards
Rogger R
 
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Old 12-31-19, 03:05 AM
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Thumbs up Welcome to our forums!

A terminal block is installed on the inside of the can when a compressor is first assembled and can not be replaced.
It is possible that the internal connector came off but more likely that the windings are burnt out.

If you use a megohmeter or insulation tester between each terminal and ground you may see a problem with the windings.
You could try a multimeter on the highest ohm setting between each terminal and ground but is not a proper test of the windings.
There should be zero continuity.
 
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Old 12-31-19, 05:12 AM
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thx for your answer Greg.

the windings are ok, no reading towards ground. I am electrician, so I am positive about that. Nevertheless I have no experience in AC systems as such.
I read that some compressors have some kind of overload protection called Klixon. I suppose they are either installed on the outside in order to be able to replace them or designed to be reset by itself...
 
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Old 12-31-19, 06:01 AM
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If the windings are burned out they often short together so you see continuity from R to S but there may not be continuity to C.
The only way to tell is to have the compressor's specs that give the resistance of the R and S windings.

Klixons are external devices so tat is not the problem.
As far as I know compressors do not have internal thermal protects but then I am far far away from knowing everything. But motors with internal thermal protects are self resetting.

Google "ac compressor disassembly"
Then give it a shot after all you have nothing to loose,
 
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Old 12-31-19, 07:24 AM
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Some compressors do have internal protection.
There is refrigerant on the inside of the compressor. To replace a terminal the refrigerant has to be recycled, and the compressor cut open.
These are called hermetic compressors, meaning they are not field serviceable.
A terminal that’s compromised or done wrong can actually react with the compressor oil, the terminal is discharged from the compressor body and can result in fire.
This compressor isn’t fixable.
 
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Old 12-31-19, 10:55 AM
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If there is no thermal protector attached to the terminal cover it will have a winding embedded one.
Also, you would for sure need at least a 1000 volt megger to be sure the windings are ok.

As said, you will need a new compressor but it really doesn't pay to replace them these days.
 
 

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