Rivacold block system

[cheecs]

Hiya,

I'm end user and we have rivacold blocksystem walk in freezer and we're having problem with the system from last few months. Compressor keeps on running and doesn't cut off when it reaches the set temperature. Instead it keeps on running untill it reaches -19 degrees.

Are there any reliable engineers available to diagnose the problem...? I'm located in Portsmouth, Hampshire.

Any help/recommendtaion would be much appreciated.

Kind Regards
cheecs

[NewmanRef]

What is your freezer set temperature? Usually a walk in freezer would be set to control between -18 and -21. The fact that the compressor does cut out would suggest it is set for -19.

[r.bartlett]

taters is down that way. I am in Newbury if you want to pay travel

[cheecs]

Newmanref, thanks for your time to reply. the temp is set to -18 and the fact is it goes up to -19 and keeps on running. It should stop as soon as it hits -18 temp but it doesn't. It keeps on running for a long period of time.

Also I have noticed that in the freezer where the two fans are, one of the fan grill has frozen water drops hanging there as well.

[r.bartlett]

It doesn't sound as if there is too much wrong. It's possible it's slightly under sized and struggling to reach set point.

However how long does it continue when it reaches -18 and what is the cut in temp ?

[install monkey]

digi controller contact welded?- when you power it up does the comp start immediatly- led on controller should flash for upto 3 mins, as for the water droplets maybe extend your defrost duration, termination temp or dripping time

[NewmanRef]

Took the words out of my mouth monkey. What type of digi control do you have cheers? Elliwel? Dixal? Either way there will be a symbol that lights to show when the compressor relay is energised. Usually next to a snowflake symbol. If your room is set to -18 this light should go out at -18. If it does and your comp is still running for a long duration it sounds as though the relay is welded and keeping the compressor energised. The other possibility is the compressor LP pressure control. Sometimes these are are a fixed pressure transducer, sometimes they are a mechanical switch. How long does the compressor continue running after -18. Generally if the relay is sticky/ welded it runs permanently. If it does cut out eventually it could well be the pressure control. Either way a good engineer will be able to diagnose quickly and repair should be fairly inexpensive. The system defrost may well not be performing as normal as a result of the compressor run fault. Get this sorted and it will probably sort the ice on your guards as well.

[r.bartlett]

he said "until it reaches -19" which suggests it does stop. I wonder if there is a compressor min run time holding it in?

[install monkey]

or diff set to above 2 deg if it does cut out- easy way to check this is to lower setpoint to -17 or -16 to see if it is that. has the setpoint been changed or is it still -18?

[cheecs]

or diff set to above 2 deg if it does cut out- easy way to check this is to lower setpoint to -17 or -16 to see if it is that. has the setpoint been changed or is it still -18?

Many thanks guys for your replies.

The cut off temp was set to -18 and it doesn't stop when it reaches to -19 it continues working and max temp we get is -20. Yesterday I have changed cut off temp setting to -15.2 and it was cutting off and starting at correct temp. Diff is set to 2 degrees so it works untill it reaches -15.2 and then stops. and starts again when temp reaches down to -13.2.

Also this morning i have seen white snow type of ice on the compressor. and I'm little worried.

help :-(

[cheecs]

digi controller contact welded?- when you power it up does the comp start immediatly- led on controller should flash for upto 3 mins, as for the water droplets maybe extend your defrost duration, termination temp or dripping time

I am unsure of how to check that digi controller contact welded or not. but when I power it up the comp starts immediately. however in the past (last year) we had turned off the freezer for around 6 hours or so and when powered up it didn't start comp immediately. it took five minutes or so before turning on the comp. the snowflake light was flashing during those five minutes.

[cheecs]

also inside freezer, I have had a look above the two fans, I am guessing thats the evaporator, there is layer of ice built up on the coil as well.

[cheecs]

Hi Guys,

Surprisingly, its working fine now. All I have done this afternoon as I went inside freezer and noticed that someone has pushed hanging temp probe which should be hanging but some how it was pushed in all the way to touching the metal plate.

I don't know whether this was the issue or not but since I Have set it back to the hanging position (touch wood) it seems to be cuttin on and off perfectly.

However I still would like an experienced engineer to check it thoroughly and may be perform general service should it be required.

Many thanks for all your help guys. I really appreciate your promptness to help resolve the issue I had. I really mean it guys. Many thanks

[Tayters]

Is that hanging one the coil probe? Might be worth checking but normally there will be a couple of probes, one to act as a thermostat and the other (wedged in the coil) to sense coil temperature which is used during defrost.

Have sent you a message to the email on your vcard.

Thanks,
Andy.

[cheecs]

and away you go, its doing it again, now this time its stuck at -15.6 and counting. I'll be calling you Andy first thing tomorrow morning to discuss and possibly you to have a look at the issue.

Cheers guys, will update you once Andy (Tayters :-) has been to look at the issue.