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Chopper86
09-05-2013, 01:06 AM
Hi

i have a small Kirby hermetic condenser unit for a drinks display cabinet that I'm currently working on.

The unit had reportedly been tripping out the customer mains circuit and the blame is on the display unit.

ive since been testing the unit for an electrical fault using my mega ohm tester.

At first I tested the compressor and that had failed and gave a zero ohm reading, so I've since installed a brand new Kirby hermetic.

The unit is still overloading and tripping out the main MCB.

Ive now tested every other component eg. Both fans, thermostat, ballasts, etc by disconnecting them and all tested fine..

please point me out if im missing something crucial here.

my fellow senior co-worker can't seem to narrow the problem either.

there doesn't seem to be any bad connections or breaks anywhere.

your suggestions would be helpfull

Thanks

Tesla
09-05-2013, 05:25 AM
How much is is overloaded amps and what is the supply circuit rated in amps. It could be an intermittent break that you cant see like a broken neutral or cable and connection. Could be when the start gear. If you had a serial number an a photo of wiring it could be helpful. I used to have an old start box made up that would start most compressors this was to confirm if compressor was faulty. Is the unit tripping out on a safety switch?

PaulZ
09-05-2013, 01:36 PM
Hi Chopper
You said it's tripping the main circuit breaker. What other appliances and equipment is running? Could it be something else? To definitely confirm it's the drinks fridge run it through a separate circuit breaker rated to the total amp draw of the fridge.
If this doesn't trip it's probably not the bottle fridge.
Paul

The Viking
09-05-2013, 01:56 PM
Another trick,

If you have confirmed that it definately is the cabinet that is tripping the breaker, install further breakers within the cabinet as a temporary measure. 1 feeding the compressor, 1 the fans another 1 the lights and so on, that will tell you where the short occurs...

Also,
Sometimes the breakers themselves fails and some breakers does not allow for compressors starting currents (Ideally a compressor should be fed by a D- rated breaker I believe)

:cool:

1mikeefc1
09-05-2013, 07:51 PM
Does it trip instantly or once the delay for the compressor is up? If its instant I would look at the mains to the unit and double check breaker capability.

install monkey
09-05-2013, 09:39 PM
had it once where condensation forming on the compressor ran and fizzed on the terminals,and caused the rcd to trip,
any eleccy htrs in the drip tray- chuck water in to see if it trips,
also a rcd should be swapped if its tripped about 9 times- see if sparkys have got a rcd tester. ensure its rated for 30ma
if the rcd is common for all circuits, get a rcd fitted onto the condensing unit as well to proove if it is ur unit or something else

had an asian petrol station tripping main rcd- pulled out all fridges,freezers ok, tried canopy lights,ok took hours, finally gained access to upstairs and found the babys bottle warmer causing it- not good at 10pm when u been there for hours

nike123
10-05-2013, 07:44 AM
(Ideally a compressor should be fed by a D- rated breaker I believe)

:cool:

My dear friend,

C - rated for starting currents of compressors and similar motors.
D - rated are current limiters with much slower reaction times.

Chopper86
10-05-2013, 02:11 PM
Thanks for all your insights and suggstions, its been very helpful.

I had found a neutral bleeding down to earth and causing the over current and subsequently tripping the breaker.

Thanks again

1mikeefc1
22-05-2013, 06:52 PM
Again I am completely confused!! Coffee? It's a chiller no?

install monkey
22-05-2013, 07:57 PM
you only mention 2 types-whats the other 3??

The number one point to consider is the type of coffee maker. There are actually five types to choose from. There's espresso maker which makes delicious, concentrated coffee. Then there's the manual drip or percolator, which doesn't brew coffee but boils it.


Thanks.

1mikeefc1
23-05-2013, 06:23 PM
A pan, a kettle then I'm out!