MCB TRipping

Hi Guys - Could do with a bit of help please.

New kitchen installed about 6 years ago by ................ sub-contract fitters.

Integrated DW and fridge on double socket mounted inside cupboard on one side of room, built in single oven plus extractor fan on other side also standard double socket inside cupboard. Hob is gas. Above worksurface sockets are on separate MCB.

Both sockets take feed from MCB previously allocated to cooker circuit.

2 nights ago MCB trips. Also RCD protecting garage circuit tripped at same time. Reset both (OK naughty) with no retrip. Been OK since until about 1 hour ago. Tripped again but RCD not taken out but 13A fuse in fridge plug blows.

Replaced fuse, reset MCB. Tripped again 10 minutes go but fuse this time still intact. No other appliances on circuit operational during any of these occurences although cooker and DW have been at times. Fridge on all time obviously.

Initial diagnosis anyone please? Earth fault perhaps or could it be the fridge itself drawing too much current. Not measured anything yet but only got multimeter.

Thanks in advance.

Cheers

R

...13A fuse in fridge plug blows....

So you have a faulty fridge (it might possibly be the flex to the fridge, esp. if a mouse has been gnawing it).

If you happen to have one of those RCD adaptors people use with lawnmowers, put the fridge through that. Check that you have the correct fuse in the fridge plug (probably 3A or 5A, should not be 13Amp).

Pull the fridge out, see if there is any visible damage, or defrost water spilling onto an electrical part. If yes, fix it.

If no, look at prices of new fridges.

are plug fuse's like rewirable in that they get weaker over time/repeated overload hence this would explain why new fuse in plug didn't blow. (Not withstanding your assertion it should only be 3a-5a)

JohnD said:

...13A fuse in fridge plug blows....

So you have a faulty fridge (it might possibly be the flex to the fridge, esp. if a mouse has been gnawing it).

Click to expand...

Or it has been trapped when fitting the appliance - I see so many pancaked appliance flexes, it's untrue.

JohnD said:

...13A fuse in fridge plug blows....

So you have a faulty fridge (it might possibly be the flex to the fridge, esp. if a mouse has been gnawing it).

Click to expand...

No mice.

If you happen to have one of those RCD adaptors people use with lawnmowers, put the fridge through that. Check that you have the correct fuse in the fridge plug (probably 3A or 5A, should not be 13Amp).

Click to expand...

Petrol mower I'm afraid. Fuse as supplied 6 years ago. Never had cause to see what was fitted before now. Wife didn't even know where it was plugged in!!

Pull the fridge out, see if there is any visible damage, or defrost water spilling onto an electrical part. If yes, fix it.

Click to expand...

Can't see anything obvious tonight with the plinth off. I'll have the thing the whole way out tomorrow.

If no, look at prices of new fridges.

Click to expand...

That's what I was afraid of!

Thanks your input John.

Cheers

markthebuilder said:

are plug fuse's like rewirable in that they get weaker over time/repeated overload hence this would explain why new fuse in plug didn't blow. (Not withstanding your assertion it should only be 3a-5a)

Click to expand...

Well I've no idea - perhaps someone else can shed some light?

Thanks Mark

Cheers

securespark said:

JohnD said:

...13A fuse in fridge plug blows....

So you have a faulty fridge (it might possibly be the flex to the fridge, esp. if a mouse has been gnawing it).

Click to expand...

Or it has been trapped when fitting the appliance - I see so many pancaked appliance flexes, it's untrue.

Click to expand...

Thanks securespark it's quite possible. I'll check when it comes out tomorrow but it's been that way since is was fitted and we've never been under there.

Oh and it hasn't done it since earlier. All instances are around the time of my first post - give or take.

The thot plickens!!

Last night - nothing wrong wth the fridge, no mice, no water no nothing. Fridge works very well off extension lead plugged into front room socket (different MCB). Thought OK. Recoonect everything xcept fridge leaving it on the xtn lead.

Reset MCB - no problems. 20 mins later - pop. Unplug everything. try reset - pop now permanent. Bugger - must be the cabling.

So this morning, get under floor tracing cables (what fun - I've just finished laying laminate flooring in the hall, u'stairs cupboard w/m cupboard and up it comes again ) back from CU. Disconnect in turn from back of each socket and try MCB. Finally it turns out to be the wretched cooker hood doing it having found and traced another cable I wasn't expecting and that's where it ended up.

Disconnected cooker hood, reconnected everything else. Reset MCB. No pop. Check out the hood tomorrow.

Just thought you'd like an update.

Cheers