True refrigerator"Freezer" Problems

Got a call yesterday evening to a restaurant that has a stainless steel double door freezer that had tripped out at the main electrical board. Arrived there pushed up the MCB fridge ran for a few min and tripped again. Pulled out the condensing unit underneath put on my gauges, pushed back up the MCB compressor ran away pulling about 6.5amps. There was not much gas in the system but it ran away. There was no pressure switches on the unit. There is a really old style manual defrost clock which I turned and forced a defrost and the unit tripped out again at which stage we presumed it was the defrost heaters. Disconnecting the defrost heater feed from the clock and pushing back up the MCB the freezer ran away and just to check it again I turned the defrost clock again and the freezer did not trip the MCB. Leaving the fridge running with the intention of returning today to fit new heaters...... Got a call an hour or so later to say it had gone down again. Arrived back today stripped the fridge down and tested and tried every combination of wirning possible but still no joy it just kept tripping. All the wirning looks good except found the mains cable damaged replaced it but still tripped out.We also eliminated all the components but still no joy...... Its not often you let a fridge beat you like this but there seemed like nothing else to try. Well having said that we could put in a new carel controller rip out the old wiring and that poxy defrost clock and start again but just in case it works now and I get a call in 2 weeks time saying fridge gone again its a big chance to take considering the fridge is about 20 years old....

Question.
1. Should I go back to the restaurant and set the fridge on fire?
2. Should I convince the man who owns it to buy a new Fridge freezer
3.Does anyone out there have any past experience with these poxy fridges and could point me in the right direction?

Cheers for any suggestions????

Was it just coinsidence when you turned defrost clock that Freezer tripped out,You stated there was not much refrigerant in system, did it run into a vacume ? as this would increase the amps.

Check to see if there is any trim heaters,I had a fosters or a williams freezer once that would intermittently trip.Found it was a trim heater around the evap housing lid.

Is it plugged in on a ring main?is the wall socket faulty.

An insulation tester and some time is needed.

Good Luck

Thanks Bernard,
I dont think it was coinsidence that it tripped when I turned it the first time because it did the same today a few times.Even when I would turn the thermostat it would trip out. One thing I never checked was the actual wall socket where its pluged in ill have to check it. It never actually ran into a vacume just stayed above. There are no trim heaters on the evap just door heaters. Ill have to check the socket tomorrow. Cheers

Hi have you tested the cabinet with a megger and what is the Reading as without this you are pissing in the wind my friend.

Hi try another outlet, the MCB could be faulty.But you should get your meggar out and check everything.

I have not got a meggar metter its something I must invest in. I got a friend of mine to have a look at it today he is an old timer and he seems to think there is a dead short in the compressor even though it was pumping for me. He also said there is another dead short somewhere else he thinks its not worth fixing unless the owner of the restaurant wants to pay for it to be rewired or else sell him a new one. Thanks for you help lads.

The True cabinets in my experience are very good and well engineered, I would say you have a trim heater or vapouriser heater fault, an insulation tester will identify the fault fairly easy, mine was £35 off ebay.

Thanks Andy ill have to pick one up I thought they cost a fortune.....

they may cost a bit but you will have more hair left on your head and a happier customer if you look proficient at what you are doing.guess work,bugger that.

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Originally Posted by Crypton

Thanks Andy ill have to pick one up I thought they cost a fortune.....

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SRW do probably the cheapest new insulation tester, about £90, I couldnt manage with out one.

its not something else on the ringmain?

th fact you had to turn the clock onto a defrost to trip it proves its not the defrost heaters, as when you got there it was tripped and was not a defrost, i would bet its a faulty condensate heater, but whats a bit worrying is you said there was not a lot of gas in the system, which means not a lot of load on the compressor and 6.5 amps sounds very high for a compressor to be running at without any load on it!!

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Originally Posted by bernard

You stated there was not much refrigerant in system, did it run into a vacume ? as this would increase the amps.

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Are you sure??? try it and i think you will find the amps are lower