walkin freezer room compressor not starting

[cassioppe]

I have a big walk in freezer room and the compressor just stoppped and will not restart. It is set up with 4 defrost periods of 30 minutes every 5 and 1/2 hours.I have emptied it and put it on defrost for the last 24 hours to ensure that it is completely unmelted but when I set it up to restart, i hear the click of the system sending its signal to the compressor but it does not start.
is there some reset on it that i need to press? Any other suggestion?

[baycuclaudyu]

Hi,
Contactors are closed, do you have power supplay, what type of compressor is ?
It is with internal protection ?

[cassioppe]

It is a Maneurop R404A, i do not much about theinternal protection and all. It says thermally protected. I have a snap shot of it and the signaletic sign but I am not able to upload it to this forum, i can email it to you if it can help-

[monkey spanners]

Do the condenser fans run at all?

You need to start working your way back from the compressor and control circuit till you get to what is stopping it running. Could be anything from a tripped mcb for the compressor power to a faulty solenoid causing the unit to go off on low pressure switch.

[baycuclaudyu]

Dear, cassioppe
Check the pressure switch (HP,LP).Probably is with manual reset .
They have red button on it .
Do you see some leakage (oil and dust) in this area ?

[cassioppe]

I feel very stupid for I have the impression that this is chinese.... Here is a snap shop of the label on the compressor. [ATTACH=CONFIG]6474
I have to check the solenoid, but do not have the tool to see if it is finished or still good, how can I check that?
the only reset button I could find was a small green sliding button besides the compressor (it said reset on it but nothing happened when I tripped it)
the big fuses on the power box are good, still all I get when the thermometer say it is time for the compressor to start is a click that usually set the compressor to on, but nothing.
no leaks that I could detect.
Am at a loss, the compressor is new from last fall, but the installator has gone out of business and I am so far out in the country side that noone can come before 3 weeks.
help is greatly appreciated

[baycuclaudyu]

For starters check solenoid valve, you must put under to voltage supplayed separately and if you hear an click the solenoid is OK.You must to check the voltage producer recomandation .You can operate in the same way with compressor contactor .Disconect compressor wires from electrical panel and check compressor contactor in A1 and A2 contacts .
Do you have any allarms (red led), in to the controller/electrical panel ?

[nike123]

I have emptied it and put it on defrost for the last 24 hours to ensure that it is completely unmelted

How did you forced it to be on defrost for 24 hours? Describe what actions did you do to do that.
Also give us model of condensation unit if it is prefabricated one.
Make few photos of condensation unit from which we could see all parts included and cold room thermostat, and post here like you posted photo of compressor.

[cassioppe]

I have set the switch on the timer so as to it to be on the defrost mode
i have changed the solenoid and it now feels warm to the touch still it will not start
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[cassioppe]

Not sure why the pictures do not show properly, will try from another web access

[nike123]

Never mind. They are showing in separate window.
Consequence of your prolonged defrost is probably high pressure switch is acted and need to be reset manually.
I see double pressure switch on top of electric box. What make and model is that switch?
Also, I see that outdoor unit is factory made. What is make and model number of outdoor unit?
What make and model number is that box near defrost timer with written "47" on it. Is that room thermostat?

I am not familiar with that Grasslin timer. It could be that beside time controlled defrost it has also temperature ended defrost and that temperature sensor could be damaged because of prolonged defrost and high evaporator temperature. That also could be reason why compressor doesn't starts.

[cassioppe]

With that 47 is room thermosthat, johnson control A419, outdoor unit is danfoss, the pressure unit with the rest is also danfoss, i have tried trippping it but nothing happens. If there are other reset switch i have not found any, do you thnik that there might be another inside the unit that i need to press? If i turn every thing back on the solenoid becomes really warm to the touch.

[nike123]

Really warm could mean (but not necessary) that shaft of magnetic valve is jammed and don't open valve when solenoid is energised. Therefore you have low pressure at compressor suction and low pressure stat is preventing compressor from starting.
You could try to change low pressure setting on Danfoss double pressure-stat (most left one) to 0 Psig or below, to see if compressor will start at all (but before mark what is its original setting).
If compressor starts, your magnetic valve is faulty and need to be changed.
Since you are not refrigeration engineer, you will need to find one to do that for you.

[nike123]

outdoor unit is danfoss
You did not wrote what is unit model #!!!

[cassioppe]

Tks everyone for the help and tips, my bro came and checked all that you have suggested, it is all beyond my competence now so I have called a Tech he will come in the morning. I will.let you know what he comes up with to fix my problem.

[richardlister]

Short of gas , out on lp I would say unless your compressor is out on internal . To check if comp is out on internal disconnect wires and check for resistance between terminals if 3ph comp they should all read the same if you are open circuit internal protection is active . Should cool and reset on it's own overnight . Have you checked your contactor could be faulty just not pulling in .check lp first if power in and out check feed to coil on contractor if feed is there but pulled in contractor is faulty . If contractor is in ensure you are getting 240 through all three phases an 410 between two.

[richardlister]

Sorry if feed is to contractor coil but it hasn't pulled in . It is faulty