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Farmelectrics
19-02-2015, 10:44 AM
Hello all I'm new to the forumn and im not an air con or fridge man im an electrician working in an fm world so work with a lot of fridge guys anyway my question is how do you mechanically test a 3 phase compressor and is there such a way I'm well aware of how to electrically test. Your thoughts please and I look forward to learning much more of you guys in the future thanks in advance

jonjon
19-02-2015, 10:46 AM
Hello all I'm new to the forumn and im not an air con or fridge man im an electrician working in an fm world so work with a lot of fridge guys anyway my question is how do you mechanically test a 3 phase compressor and is there such a way I'm well aware of how to electrically test. Your thoughts please and I look forward to learning much more of you guys in the future thanks in advance

I thought an electrician would know this ?

Farmelectrics
19-02-2015, 10:51 AM
Jon Jon I have tested the compressor electrically for a fridge engineer who didn't no how to test it he was saying to me that it could be still mechanically damaged hence my question is there a way of doing this or is the guy talking rubbish

Farmelectrics
19-02-2015, 11:20 AM
Apparently the above compressor is now damaged even though when I tested it with my mft it was ok so back to my question how can a compressor be mechanically damaged go easy I'm not a fridge guy lol

Farmelectrics
19-02-2015, 11:51 AM
I'm now gathering the only way to test a compressor is by using a multi meter and or a megger is that right

Rob White
19-02-2015, 01:27 PM
I'm now gathering the only way to test a compressor is by using a multi meter and or a megger is that right

to test a comp electrically, you need to test like you have.
Test to earth and test across the windings, if all tests ok the
compressor could still be seized so pulling Full Locked Rota Amps.

If the compressor is mechanically faulty it would be ok electrically
but would not rotate or if it was rotating, it might not be pumping.

Rob

.

monkey spanners
19-02-2015, 03:08 PM
For mechanical testing it would be running it, listen for noises, see how well it pumps into a vacuum and how high the head pressure can go, watch the run current doing this. Shut it off and see if any refrigerant bleeds back across the compressor (note that its normal for some to do so in scrolls and rotaries)

If it sounds like this its bad,

https://www.youtube.com/watch?v=EpOZXEfByfE

jonjon
19-02-2015, 09:13 PM
Jon Jon I have tested the compressor electrically for a fridge engineer who didn't no how to test it he was saying to me that it could be still mechanically damaged hence my question is there a way of doing this or is the guy talking rubbish

Sorry read it wrong I thought it said how do you electrically:( test

Farmelectrics
20-02-2015, 06:59 AM
thanks for replys chaps not trying to invade your world of refridgeration ha ha happy as a spark just trying to learn basic stuff thanks again

Farmelectrics
20-02-2015, 07:04 AM
out of interest what would cause the compressor to seize

RANGER1
20-02-2015, 08:16 AM
Liquid flood back
No oil
to hot lack of refrigerant

To name a few

Glenn Moore
20-02-2015, 09:48 AM
Hi Farmelectrics
I wrote a series of short lectures on WHY COMPRESSORS FAIL there are 9 parts to the series. You can get them from the Danfoss.com website, Business Areas, Refrigeration & Air Conditioning , Technical Literature,Field Service Tips, Field Service Notes , you will see a no of Field service notes that I wrote before I retired from Danfoss. These may be helpful for your further knowledge into refrigeration Kr Glenn. Any problems finding them let me know and Ill send them direct by email , ps These are also on Google under Glenn Moore Why Compressors Fail

Farmelectrics
20-02-2015, 10:47 AM
thanks for your help glenn