How to Test a compressor.....

[Teknicool]

Hi guys,

I have had around 6 different chaps explaining 6 different ways to test a compressor. Some use a megger, some a continuity meter, some I am sure make it up as they go along.

Can anyone tell me, in detail how to professionaly test a compessor.

Thanks

TC..

[Grizzly]

Teknicool.
Follow the link I have placed below. It covers a lot of testing options.
Definately use a megga a multi meter is only recomended if it is sensitive enough.
Grizzly
http://www.thermagroup.com/compressors.php

ps look at the bottom of the webpage.

[Latte]

Easy to show - slightly more difficult to explain

First of all 240v compressor. Obviously a megger is the best way to test but no everyone carries them so with a multimeter. First, Check all 3 points against earth. Obviously you shouldnt get a reading on any.
Secondly, Take the 3 points of the compressor and measure between them. 2 of the readings should add up the 3rd so for example the 3 measurements you might get are 6 ohms, 5 ohms and 1 ohm, This is therefore OK as measurements 2 & 3 add up to the first.
On a Three phase compressors all 3 measurements should be the same.
This obviously only covers the electrical side of testing, not the actual pumping capacity, but judging by youre post this is what you are looking for.
I hope this makes sense, it does in my mind but if someone can translate from Essex boy to English then please be my guest. If it doesnt make sense please post

Regards

Raymond

[Teknicool]

Thanks Raymond, makes perfect sense

regards
TC

[Teknicool]

Thanks grizly, excellent info.

Regards

TC

[Mik Dundee]

remove cable from the comp terminals, then test with a megga , ohmmeter and follow the instructions from rdocwra. if your condeming a big donk best use a megga testing to earth you dont want any condinuity..

[M.Amer]

hi thier is another way 2 quik check g/d burn compressor if u dont have any tester.connect manifold gauge hose to suction servic valve side n remove slite ref..in smal container notic oil colour,if black carbone n pungent smell it indicats compressor burnt out .

[rothmans]

Hi
Greezly iam a new member to this forum. The link does not exists can any one send me some document to check and test the winding.

[chemi-cool]

Thats for electrical testing only.

I can only add that you need to know the resistance of the windings, the resistance of the start windings [on single phase only].

Apart from that, there are other things to test such as oil, flappers, oil filter, oil pump, vibrations.

[Grizzly]

Hi
Greezly iam a new member to this forum. The link does not exists can any one send me some document to check and test the winding.

try this one

http://www.mediafire.com/?sharekey=0...bc030e61882200

Enjoy Grizzly

[lowcool]

id be lost without my meggar,its a basic must have tool,especially where eletrical compliancy is concrned

[Magoo]

I agree with Lowcool, a meggar is essential to get factual information , if a single phase dome or a 100 + Kw 3 phase motor. I use a Fluke cat3 multi meter and an Avo electronic meggar, set up a peg board with a range of set resistors so as to reference accuracy.
magoo.

[lowcool]

good fun for apprentices as well,hold this while i turn the handle.

[Magoo]

Lowcool . You are a sick buggar, fun though as you said, especially set on 1000 volts.But hell are you still using one of those windie windie, meggars. Drop into the 21 century, go electronic Avo, good gear but not cheap.

[lowcool]

gday magoo strange how they instantly have a good regard for electricity and components,i myself got stung with a start capacitor before discharge resistors were the norm,only mentioned the crank as thats what was around in them days,i will stick to my analogue only had to have movement replaced once in the past 11 years or more

[D.D.KORANNE]

What about the other tests on compressor ? Like displacement , reed valve leakage etc . ?

[lowcool]

read the post

[kinz]

I recenty tested a 1ph compressor 2ohm 6ohm and 100hm, 2ohm out so thort the comp was U/S. when another eng replaced the starter it run??? there was no leakage to earth any one no what the allowable diff is?

[B G Scott]

I recenty tested a 1ph compressor 2ohm 6ohm and 100hm, 2ohm out so thort the comp was U/S. when another eng replaced the starter it run??? there was no leakage to earth any one no what the allowable diff is?

PM me I am on your door step.

[Andy78]

thanks grilly for your mediafire link

[rickyb]

Hi all i tested a 3ph compressor with a meggar and got a dead short on all 3phases. Got a phone call today from another engineer changing the pot for a new one. Who told me he could find no short with his multi meter! Starting to doubt myself now!

[Tayters]

Was it a dead short or were the windings just a low resistance?

[old gas bottle]

well you must have tested it for a reason !and i,am thinking all 3 phases were present,so its was probley siezed was it ?

[monkey spanners]

Hi all i tested a 3ph compressor with a meggar and got a dead short on all 3phases. Got a phone call today from another engineer changing the pot for a new one. Who told me he could find no short with his multi meter! Starting to doubt myself now!

Unlike a megger, a multimeter doesn't have enough volts to find shorts on mains equipment.
So long as you tested with your megger between any of the three compressor terminals (wires removed) with one test lead, and with the other test lead on a good earth and got a low reading (below 1 megger ohm (ish) it should be way above this) the the compressor has took a dirt nap.

What was the reason for the call to site?

Have a look on youtube for compressor earth test vids.

Jon

[lencoo12]

I recenty tested a 1ph compressor 2ohm 6ohm and 100hm, 2ohm out so thort the comp was U/S. when another eng replaced the starter it run??? there was no leakage to earth any one no what the allowable diff is?

[Amopower]

I am getting resistance readings for all three combinations of 274Kohm, 275Kohm, and about 5 ohm. Those two very high readings imply that the compressor windings are shot, I assume?

[Tayters]

If it's a single phase compressor then 1 winding is faulty.
If it's a three phase compressor then 2 windings are faulty.

Which type is it you have there?

Cheers,
Andy.

[nike123]

Is compressor been still hot when you tested it?

[nike123]

I recenty tested a 1ph compressor 2ohm 6ohm and 100hm, 2ohm out so thort the comp was U/S. when another eng replaced the starter it run??? there was no leakage to earth any one no what the allowable diff is?

Your reading depend on accuracy and repeatability of your instrument.
Also, you need to have clean connections with no humidity,dirt, oil, grease etc...

[kheilan]

sir a good day to us when you read my post in here.... . . . .i have a problem a 3hp reciprocating compressor using in the reefer container van model carrier... . . .i see abnormality because when i turn ON my unit i hear a abnormal noise after 5seconds it turns to normal noise, 10mins when i start the unit the suction side or winding side of compressor start to ICING and then after 3hrs the unit have a slow cooling in the unit... . . .i want to check the compressor if there's a broken valve or anything in mechanical side and how can i do it with less time and movements from my compressor , and can i ask what is the good reading from megger from winding....i hope you could help me tnx

[nike123]

Check subcooling, superheat and amperage to see if it is overcharged with refrigerant.

[nike123]

and can i ask what is the good reading from megger from winding....i hope you could help me tnx

Good reading is voltage of your power source times 1kOhm and above.

[shooter]

Short answer

check the expansion valve or bulb probably broken sensorline.

[piercent]

Although it's not focused specifically on compressors Megger just put out an article on insulation tester safety that might be useful. It covers IEC 61010-1, CAT ratings, equipment evaluation, risk, and what constitutes safety. Here's the article: http://www.newark.com/pdfs/techartic...sterSafety.pdf as well as their product page: http://www.newark.com/megger