Please help

[BigRich]

Hi All,

I hope you can help - I seem to have a pretty bad problem.

Two nights ago our circuit breaker tripped, which tripped the main breaker and plunged the house into darkness. Obviously I lowered the problematic circuit and switched on the rest of the electrics. No problem.

However, the problem circuit happens to have every single socket in the house (over 3 floors) attached to it - so effectively we have no fridge, TV, kettle, oven, phone, etc etc etc.

We also have had some issues with Damp in our lower ground floor and initally I was thinking this was the problem as one of the sockets had damp surrounding it. Therefore I have taken the socket panel off the wall and sure enough there was a substantial amount of dirty and rubbish in the box - I cleaned up the contacts the best I could using a plastic knife and left the face unattached to the back, hoping to dry out the wire (not that they sparked or appeared damp in anyway. I also unplugged everything from the circuit over the 3 floors (oven, fridge, washing machine etc etc)

I left the problem circuit off a few hours and then switched it back on - all was ok for about 24 hours, it's now popped again, and I'm beginning to have my doubts regarding the problem socket. I've even swapped the circuit breaker to another 32 amp one, but the same problem arises.

I've bought a termination block, and I've attempted to unwire that socket and terminate the live, neutral and earth wires onto it - I have 3 wires and I terminated each one into a seperate hole on the block (is that correct?!?)

Question is, if it is that socket, how do I safely contain it and get the circuit back up. If it isn't that socket then what can it be?

I've performed zero amount of DIY over the past few months, so it cannot be new nails, or me messing around with everything...

Please help! I'm reluctant to phone an electrician at this time, as I don't want to be ripped off.

 

[JohnD]

Are you saying that the RCD trips even when you have all appliances unplugged?

 

[BigRich]

RCD being the circuit breaker for a specific ring? Then yes - I have unplugged all appliances and then tried it, and it's still popped...

 

[JohnD]

RCD being the circuit breaker for a specific ring? Then yes - I have unplugged all appliances and then tried it, and it's still popped...

that's not quite what I meant...

Have a look at the pictures I posted in
//www.diynot.com/forums/viewtopic.php?t=61589&highlight=style
and see if you can identify the thing that is tripping. Also tell us what is written on it (per the list of possible things I posted) and its appearance.

 

[BigRich]

RCD being the circuit breaker for a specific ring? Then yes - I have unplugged all appliances and then tried it, and it's still popped...

that's not quite what I meant...

Have a look at the pictures I posted in
//www.diynot.com/forums/viewtopic.php?t=61589&highlight=style
and see if you can identify the thing that is tripping. Also tell us what is written on it (per the list of possible things I posted) and its appearance.

Sorry John, thanks for the help.

I've looked at the images: There doesn't appear to be anything that I'd say is a 'main switch' what we do have is an RCD (with test button) that when trips all the electrics are switched off. However, it looks like the 34amp MCD (which all sockets are run off) has the fault, as this is the one that is causing the tripping. I found this out, by reseting the RCD, and flipping the 34amp MCD to off and then switching the RCD back on. We have lights and nothing trips, therefore it must be something on the 34amp circuit?!?

 

[JohnD]

You mean it is the RCD that trips.

But if you turn off the Socket Ring with the 32A MCB, the tripping stops.

OK.

And you say it still trips if you have unplugged all the appliances from the sockets, and switched off any fixed appliances, like coookers or heaters, on that circuit?

Then you probably have a wiring fault. Might be mice gnawing through a cable, might be nail penetration, might be water.

Does it alway happen immediately, or is there a random delay?

Start by having a look round the kitchen, bathroom, utility room - anywhere with water - for signs of a leak that could have reached anything electrical (this might be under the floor). Esecially round the washing machine.

If you have cleaned out the socket in the basement (I find a dry paintbrush very useful for that) then it is probably not the cause.

Look for any Junction Boxes.

Also have a look behind all the sockets and FCUs for a loose wire that might be touching the back box or a wrong terminal, or any cracked or damaged fittings, or any outdoor sockets or pond supplies.

Earth Leakage faults can be fairly difficult to find without the ight skills and equipment, so start asking your friends and neighbours if they know a local electrician they would recommend.

 

[BigRich]

You mean it is the RCD that trips.

But if you turn off the Socket Ring with the 32A MCB, the tripping stops.

OK.

And you say it still trips if you have unplugged all the appliances from the sockets, and switched off any fixed appliances, like coookers or heaters, on that circuit?

Then you probably have a wiring fault. Might be mice gnawing through a cable, might be nail penetration, might be water.

Does it alway happen immediately, or is there a random delay?

Start by having a look round the kitchen, bathroom, utility room - anywhere with water - for signs of a leak that could have reached anything electrical (this might be under the floor). Esecially round the washing machine.

If you have cleaned out the socket in the basement (I find a dry paintbrush very useful for that) then it is probably not the cause.

Look for any Junction Boxes.

Also have a look behind all the sockets and FCUs for a loose wire that might be touching the back box or a wrong terminal, or any cracked or damaged fittings, or any outdoor sockets or pond supplies.

Earth Leakage faults can be fairly difficult to find without the ight skills and equipment, so start asking your friends and neighbours if they know a local electrician they would recommend.

I think I'll will double check that it cannot be appliance based - which I'm 99% sure of anyway.

There is a variable rate of which it trips: for example I tried this morning a couple of times and on one occasion it didn't trip for 3/4mins. The next time I tried it tripped in 15 seconds. What does this tell me if anything?

 

[JohnD]

It is probably not a very strong leakage. But it might be intermittent. Quite likely damp.

BTW, use the

button, not

 

[Adam_151]

Do you have any big loads like electric cookers or electric instant showers, immersion heaters etc?

If so, with the 32A MCB for the sockets switched off, switch lots of heavy stuff on and see if you can make the RCD trip, this should hopefully rule out a neutral-earth fault if nothing trips.


The timing thing makes it sound like there is a heating element involved, if the fault shows itself when a certain temp is reached, the time to reach that will depend on the starting temp, which will be dependant on ehwne you last tried it. Have a look round for things on that circuit that you might have forgotten to switch off/unplug

 

[BigRich]

Ok John, thanks again.

You have been very helpful, I do think I'll have to get in an expert, as I've probably reach the level of what I can safely achieve. I just hope I don't get ripped off - I know this is very much a "stick the thumb in the air" but what kind of charges could I expect?!?

 

[Pensdown]

The 32amp MCB will only trip on over current so you must have a real fault somewhere as apposed to just an earth fault.

Personally I don't think it's a damp problem because normally only the RCD would trip.

Can you let us know what you loose when you turn off the problem MCB

Some examples

No hot water?
No washing machine?
No Boiler?
No Cooker?
No Shed/Garage power?

 

[JohnD]

Sorry, don't know. Best thing is to go on personal recommendation of someone who appears to do a good job and to be trustworthy. A local person. A qualified electrician not a general builder or handyman. Adverts in the local paper are not the best guide. Make sure they do not have a £100 call0out fee.

With the right testgear and skills he will probably find it quickly, and will have repaired dozens of faults like yours.

 

[JohnD]

The 32amp MCB will only trip on over current so you must have a real fault somewhere as apposed to just an earth fault.

Hi, Pensdown.

As I read the OP, it is the RCD that is tripping, but if he turns off the 32A MCB, then the RCD doesn't trip. So it seemed to me to be a P-E fault on the socket ring.

Isn't that right?

 

[BigRich]

Thanks for the help guys:

As far as I can work out, I have maybe 5 MCDs in the house, and one RCD.

4 MCD's are 6amp and the different floors lighting and boiler are connecting to these - I really don't think they are the problem, as I can have power to these rings and nothing trips.

I also have 1 MCD (32amp) which seems to have everything else! (I live in a old terrace house, with no outside power. The house is split over 3 floors, lower ground (which is subterrean at the front of the house, but ground level at the back.) ground floor, and then first floor.

All sockets on all three floors are running of this 32amp MCD. I also think the electric oven runs off that too. And then just the usual appliances (Washing machine, TV, computer, phones, table lights, kettle, microwave etc etc) I have no electric shower, so I think the main thing is the oven.

Like I mentioned, when it first occured, I cleaned out the rubbish from the back of that dodgy circuit (which I think is a spur on the ring) and it didn't trip for 24 hours. but it's now tripping pretty regular, basically overnight that MCD was switched off all night, and I tried it first thing in the morning and it lasted about 4 mins before tripping, I left it for 10mins and tried again and it tripped in 10secs.

An ideas?!?

 

[Pensdown]

Two nights ago our circuit breaker tripped, which tripped the main breaker and plunged the house into darkness

I left the problem circuit off a few hours and then switched it back on - all was ok for about 24 hours, it's now popped again, and I'm beginning to have my doubts regarding the problem socket. I've even swapped the circuit breaker to another 32 amp one, but the same problem arises.

I read the post thinking the MCB (circuit breaker) tripped first which then tripped the RCB (main breaker)

Rich, can you confirm if the 32amp MCB (breaker) has tripped (even once) or is it just the RCD (mains switch) that is tripping?