freezer trips power on one circuit but not another; why?

[69xians]

Hi, I've just moved a chest freezer into my business unit which I previously had working at home with no problems. I came in the next day and found that the socket circuit had tripped, so I plugged the freezer into an extension cable and ran that from the upstairs socket circuit (separate circuit) to try and eliminate the freezer but it's worked absoultely fine and not tripped the power. So I tried plugging the freezer into a different socket on the original circuit and again it tripped the power. What's going on? Thanks for any help or advice. Cheers

 

[kevindgas]

several factors could be the cause

MCB may be failing
MCB may be incorrect size or type
loose connection somewhere in circuit
socket could be faulty

without the information on the 2 Consumer units it has been connected to it is difficult for any of us to advise properly.

 

[Aragorn84]

Could be an RCBO/RCD and combined earth leakage is pushing it over?

Or theres already a few devices on the downstair ring main and when they all happen to fire up together they trip the breaker?

Some pics of the board and an idea of whats plugged into ti might help.

 

[RF Lighting]

Or a crossed connection on the socket, or damage to part of the cabling on the circuit.

 

[bernardgreen]

I've just moved a chest freezer into my business unit

Suggests there are computors and other office equipment which are likely to have power supply units with mains filters on the inputs. These will be creating a im-balance in the RCD but less than the trip value. Add the earth leakage from the freezer to the circuit and the im-balance will be enough to trip the RCD.

 

[Steve]

The answer as I read it is simple.

The freezer has an earth fault, and the upstairs sockets are NOT RCD protected.

 

[69xians]

Thanks for all your thoughts. Just some further info; the circuit has just had a full electrical inspection and certificate for clean bill of health. I've only had 3 items running off the circuit whereas it can cope with many more and normally does. I've tried plugging the freezer into other sockets on the same circuit with the same results, ie: tripping but other appliances plugged into these sockets are fine. I forgot to mention that the extension cable I ran from another circuit does have an rcd on the extension but as I said previously, it didn't trip the rcd or the mains!? Does this mean it's as Steve suggests and that the freezer has an earth fault? Cheers

 

[electronicsuk]

Does this mean it's as Steve suggests and that the freezer has an earth fault? Cheers

Assuming the RCD on your extension leads works properly, an earth fault now seems unlikely on the freezer itself. It might be worth having it PAT tested just to rule out any obvious problems with the appliance.

 

[69xians]

It's weird, it just doesn't seem to add up, I've had the freezer plugged into for 3 previous years with no problem, it was PAT tested just over a year ago but now that I've moved it, trips one circuit but not another. As I say, weird.

 

[securespark]

Get it PAT tested again, then. It could easily be faulty.

Please confirm whether the sockets into which the feeezer was plugged when it tripped are RCD protected.

What tripped? An RCD/ RCBO or an MCB?

 

[69xians]

Ok, I may be a bit out of my depth with the jingo. I know what an RCD is but I don't know what an RCBO or MCB is. All I do know is that there is a very modern looking box on the wall with switches for upstairs sockets, downstairs sockets, upstairs lights, downstairs lights and separate circuits for hardwired dishwasher, oven, walk-in fridge and two 3-phase circuits. I'll look into getting things PAT tested again. Cheers.

 

[securespark]

OK, fair enough.

How wide was the thing that tripped?

What was written on the front of the thing that tripped?

 

[Aragorn84]

As i said in my earlier post, snap a photo of the board, and tell us exactly whats plugged into the upstair and downstairs circuits.