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View Full Version : HELP Compressor seems fine but will not work!!!!!!!!!!!!



curlywoody
27-02-2008, 01:18 PM
I would love someone to help me. I have been working on a commurcial fridge/ freezer.

One side is a fridge and the other is a Freezer.

The problem on the fridge side of things first of all . When we got there the Fans were working but the compressor was not. We looked for the solution.

Checked the ohm on the C-R-S and they add up correctly. So this must be fine. I then replaced the Relay and Capasitor O/L was in the relay I think as was no external Overload protector.

NEXT

Nothing. So I have already checked pressure and added the correct amount of Refrigerant R22.

Looking at the next problem we seem to have 2 solenoid valves and magnets on mmmmmm.

one from the comp out and the other ? I have never come across this before.

So we replaced just the elecromagnets.

Guess what one near the comp clicked but the other seemed not to COULD THIS BE THE PROBLEM.

So i swapped the magnets and then got the click on the first one again but not on the other I dont think.

IS THERE ANYTHING ELSE I COULD CHECK OR I HAVENT DONE WE NEED TO GET THIS FIXED AS THE EQUIP IS WORTH 8000 POUNDS.


PLEASE help :confused:

paul_h
27-02-2008, 01:48 PM
compressor seized?
Have you verified the compressor is getting any voltage at the terminals?
Is it drawing any current?
Is it drawing a lot of current and activating the overload?

edit: could even be a control problem, maybe the t/stat or controller isn't giving full voltage or any volts to the compressor

curlywoody
27-02-2008, 01:58 PM
I really am unsure about any really sorry i am a pest.

There was resistance showing from the comp. Also there is power to the relay. There is no clicking any where near the relay?

How would i check if it is seized?
Cant get into the comp as sealed unit.
How can i unseize it. All i know the the bar owner has just took over the place and was empty for 12-18 months. the wiring looks like someone had been in a few years ago also.

Help

curlywoody
27-02-2008, 02:07 PM
Unsure really.

Fans and solenoid getting power and relay. also...

seized could be there seems to be quite a great deal of psi pressure showing on the guages as i can remember.

Should we maybe vacum and regas???????

unsure. Could be looking to far into it. Thinking Back when we got to it there was no or not much gas in.???????????

I am quite new to the game had the training but still learning every Job.....

paul_h
27-02-2008, 02:37 PM
OK, so the compressor is not open circuit.
and you replaced the relay and the capacitor with the correct type
There is no external overload
The relay is getting full operating voltage

Is this a little compressor with the relay on the compressor terminals?
Or is this a larger unit with a relay in a separate junction box and a start and run capacitor?
If it's the latter, check both capacitors and make sure the relay is the right way up.
If it's a small unit, I'd say it's seized.

If you had an "annie hermetic analyser" you could try to unsieze the compressor by rocking it backward and forward.
Probably not worth buying one just for this job though. If it was short of refrigerant or had a blocked condenser/faulty condenser fan motor, the compressor is more than likely beyond saving, ran too long under bad conditions and locked up good I'd say.

curlywoody
27-02-2008, 03:01 PM
You are brill mate.

The relay is correct and wired right. there is only one capacitor on it.

I will try and rock if not then new one.

The comp is not very small not too big. sc-12d think

DarrynA
27-02-2008, 04:46 PM
take the solinoid coil that is not "clicking" and test on the 2 outside poles with your tester on ohms and see if there is a reading. if not u know the coil is dissed so try replacing the coil and that SHOULD solve your problem:cool:

Gary
27-02-2008, 05:37 PM
I would love someone to help me. I have been working on a commurcial fridge/ freezer.

One side is a fridge and the other is a Freezer.

Are they working off the same compressor or separate units?


The problem on the fridge side of things first of all . When we got there the Fans were working but the compressor was not. We looked for the solution.

Checked the ohm on the C-R-S and they add up correctly. So this must be fine. I then replaced the Relay and Capasitor O/L was in the relay I think as was no external Overload protector.

A current type relay won't work if it is upside down. Is it right side up?


NEXT

Nothing. So I have already checked pressure and added the correct amount of Refrigerant R22.

How can you check pressure if the compressor isn't running? How did you know how much refrigerant to add?


Looking at the next problem we seem to have 2 solenoid valves and magnets on mmmmmm.

one from the comp out and the other ? I have never come across this before.

This doesn't tell us anything. In what lines are the solenoids located? Describe the locations for us. We can't see it from here.


So we replaced just the elecromagnets.

Guess what one near the comp clicked but the other seemed not to COULD THIS BE THE PROBLEM.

Near the compressor doesn't tell us anything. In what line is the solenoid?


So i swapped the magnets and then got the click on the first one again but not on the other I dont think.

IS THERE ANYTHING ELSE I COULD CHECK OR I HAVENT DONE WE NEED TO GET THIS FIXED AS THE EQUIP IS WORTH 8000 POUNDS.

Without an accurate description of the system, we can only take wild guesses.

Gary
27-02-2008, 05:40 PM
Here's my wild guess for today:

The solenoid that is "near the comp out" is a hot gas solenoid for defrost and it is powered. The defrost timer is stuck in defrost... or not.

Dr._Fleck
27-02-2008, 06:09 PM
I remember when i was fresh out of college, i got a job and was sent straight out in a van, it's not nice.
All i can say is don't rush, don't panic, work your way through the system one fault at a time. Snip cable ties off and trace the wires back to see what they do.

Gary
27-02-2008, 06:40 PM
I remember when i was fresh out of college, i got a job and was sent straight out in a van, it's not nice.
All i can say is don't rush, don't panic, work your way through the system one fault at a time. Snip cable ties off and trace the wires back to see what they do.

Ahhhh... memories.

As I found out much later, my boss had a nightmare system set up in an unused portion of an industrial site. It had every gadget imaginable on it and every conceivable problem. This was the first "service call" he sent all his new techs on. I wonder if anyone ever got it running right... I sure didn't... LOL

curlywoody
27-02-2008, 07:35 PM
Thanks will check all poss and keep you all posted. most of the information is from memery as going to try tomorrow will no more then. n

Cheers and speak asap..

grump
27-02-2008, 07:35 PM
Dont try this at home,disconnect the compressor wiring push its contactor on with a screw driver check you are getting volts, reconnect the wiring hang a clamp meter over the compressor feed,reconnect the compressor wiring,push the contactor in with your screwdriver let me know what transpires ps use a long driver and wear eye protection,the clamp meter will tell you if the compressor is seized.also check the windings and any capacitors in circuit. Grump:D:D:D

Brian_UK
27-02-2008, 09:23 PM
Also, confirm that you have a neutral as well as a live.

frank
27-02-2008, 10:01 PM
Also, confirm that you have a neutral as well as a live.

And INSURANCE :D:D:p

get the gauges
28-02-2008, 01:09 AM
This doesn't tell us anything. In what lines are the solenoids located? Describe the locations for us. We can't see it from here


Take a video of the fridge and post it on utube for all to see .

Todays wild guess's

Does the Compressor neutral run through the klixon, check that it is continuous,unless that is you changed it with the new relay,i'd put the original relay on if you don't think that was faulty.

Does the comp get warm or hot
does the klixon (round black cup against the comp body) make a sound just after the power is applied.If it's seized then this has got to be listened for ,it's not going to happen again until it's cooled down. If you have power at the terminals and the klixon is in the neutral then thats first thing to check but if it is burnt out the comps seizing anyway.
Is there an L/P pressure switch or two, is it a pumpdown system?,if not, then the solenoids are defrost hot gas and a timeclock is energising one of them,why not both?are there two timeclocks?

1mikeefc1
29-02-2008, 09:05 PM
Compressor siezed. once its been replaced make sure sol valves are on in the correct order as it is the hotgas valve and other is fed by the controller for fridge cycle.

Electrocoolman
05-03-2008, 02:11 AM
Back to basics...

What is MAKE and MODEL of compressor?

You thought it might be a SC12?

Are your winding resistance measurements across C-R and C-S individually (or have you only measured across R-S) i.e. is internal overload Open Circuit or OK.

As Brian says have you got a Neutral to the compressor as well as a Phase? (measure voltage at relay connections)

Have you tested the start Relay...assume current type. Is it the correct one for the compressor?
Is the Start capacitor the correct value (80mfd on most Danfoss) ....wired correctly to relay?

Does the compressor make any noise on applying power?

What sort of control system does this unit have? Electro-mechanical (ie thermostat, timeclock) or electronic? If electronic is there a contactor / relay between controller and compressor?

If this unit has two compressors for Fridge and Freezer sections, is there a delay timer to prevent both compressors starting together?

More info required from tracing out circuit (electrical and refrigeration)

Whats the callout rate to Tenerife if its worth 8K !!!