serve over problem

[Andy AC]

Having an annoying/expensive problem with serve over unit. Its eating electronic controllers, keeps burining out/dead shorting across compressor out/neutral terminals on back of controller.It first happened about 8 months ago, factory fit controller packed up. Cleaned condenser-never been done before, and fitted new eliwell controller. Ran fine for a couple of months, got called back to it, controller had caught fire/burnt out-looked like water damage. Had a new controller in the van, replaced, checked comp run amps - all ok. Ran fine for a month or so then the same thing happened, again looking like they had spilt liquid all over it. Put another controller in it, checked amps etc. all seemed fine. This time the controller terminals just melted. To eliminate possibility of compressor amps being too much, I fitted an LAE AT1 with a 16a onboard comp relay, and an additional 30a relay from a fujitsu a/c unit. Thought this would do the job as comp current now not going through controller, checked amps etc, all fine, completely sealed control panel with silicone to stop them from spilling anything on it. - 2 weeks later controller burnt out across comp terminals- aarrggh!
What's going on? It's driving me mad.
I haven't got any info on unit, can't find data plate. All I do know is that its about 3 years old, dual evaps - display area controlled by electronic control, under display storage controlled by mechanical stat.
Any ideas anyone?

Andy

[Andy W]

I have had exactly the same, mine was on a service cabinet with the controller in the kicker plate and when the customer was lifting bowls of food in water in and out of the fridge then it was spilling, I ended up making a plastic cover to protect the controller from spills and warned the customer to be more careful.

What make and model of cabinet is it?

[al]

if the controller is jammed into a tight space this can lead to burn outs as can sealing the top/back with tape as i've found to my cost!!

is it 220v? might it be worthwhile fitting a 12v in case its mains voltage related, at least that way all you're changing is a tranny.

al

[taz24]

Having an annoying/expensive problem with serve over unit. Its eating electronic controllers, keeps burining out/dead shorting across compressor out/neutral terminals on back of controller.It first happened about 8 months ago, factory fit controller packed up. Cleaned condenser-never been done before, and fitted new eliwell controller. Ran fine for a couple of months, got called back to it, controller had caught fire/burnt out-looked like water damage. Had a new controller in the van, replaced, checked comp run amps - all ok. Ran fine for a month or so then the same thing happened, again looking like they had spilt liquid all over it. Put another controller in it, checked amps etc. all seemed fine. This time the controller terminals just melted. To eliminate possibility of compressor amps being too much, I fitted an LAE AT1 with a 16a onboard comp relay, and an additional 30a relay from a fujitsu a/c unit. Thought this would do the job as comp current now not going through controller, checked amps etc, all fine, completely sealed control panel with silicone to stop them from spilling anything on it. - 2 weeks later controller burnt out across comp terminals- aarrggh!
What's going on? It's driving me mad.
I haven't got any info on unit, can't find data plate. All I do know is that its about 3 years old, dual evaps - display area controlled by electronic control, under display storage controlled by mechanical stat.
Any ideas anyone?

Andy


I would go down the route of customer damage.

I would move the controler to somwhere where the customer can't get any fluids on it.
It could be from cleaning or spillage but to prove it is water I would move it away.

taz.

[Andy AC]

The controller can breathe, I have only sealed the panel on the cabinet - all round the switches and front of the electonic control. I have drilled some ventilation holes in the bottom of the panel.

Andy

[Brian_UK]

May be off the wall but.....

Having 'sealed' the cabinet where the controller it is possible for temperature changes in and around the panel to create a pressure differential between in and outside the panel.

This can move moisture through the cables, between the cores, and into the panel cabinet.

Not saying that it is but something else to worry about.

My best bet is the dreaded kitchen cleaner who throws buckets and buckets of water; generally at the floor but not always.

[lowcool]

even check underside of cabinet base for water traces,had an isa gelati display intermittently tripping breaker,it always meggared ok,found small water stain sort of over the mains terminal strip.one drip and bingo trips again.cab had bad seal of penetrations and wet insulation.

[Andy AC]

Haven't been back to it yet but just had a thought - could a neon indicator light cause this much of a problem?, its the only other thing on the compressor circuit.

Andy

[Magoo]

If the compressor current is going through the controller, and controller is stuffed in a small hole and is subject to the cleaner throwing water around at kick strip level. You have answered your own question.
Install a remote contactor that is driven by controller, add a semi -water resistant facia [ flip flop thing ]. I am fairly sure the controller is not IP 56 rated.
magoo