RCD tripped - sockets issue?

[Northbeach]

Hi,

The mains went off this morning whilst my kids were having breakfast (and watching the tweenies).
Thought one of the mcb's had tripped, but it turned out the RCD had switched off. Isolating the problem, it only affects the mains sockets - with the sockets mcb off, the RCD will happily switch back to on (with the mains off the rcd will also remain on - as soon as the sockets mcb is flipped on, the rcd will trip.

CU had 2 x lighting, 1 x garage, 1 x heating and 1 x mains sockets (not split between floors. Only thing added to the mains was a new TV added last Thursday.

CU make is: Marbo 12 way (max load 80a)
RCD 63a

Case of turning the mains off and checking each socket for faulty wiring, or possible faulty RCD?

Apologies if there are any typos...no electric = no computer and router (typed on phone)!

Many thanks.

 

[Chri5]

Unplug everything on the circuits, isolate all spurs ,energise the rcd- if it stays and doesnt trip it's a plug in or spur connected device issue.

If it trips with no devices plugged in, its a component or wiring issue.

 

[Northbeach]

Unplug everything on the circuits, isolate all spurs ,energise the rcd- if it stays and doesnt trip it's a plug in or spur connected device issue.

If it trips with no devices plugged in, its a component or wiring issue.

Thanks Chris - yes unplugged every device, but it still trips (doesn't stay on).
Will check the sockets for issues now.

Cheers.

 

[Northbeach]

Checking each socket - two so far seem ok - if it's a faulty socket/switch (feasible?) would it be a case of wiring a new one to each point (using same one) and eliminating that solution?
Initially thought it was a cheap fleabay iPod charger my daughter was using - seems to get 'stuck' within that socket when trying to unplug - led me to believe it my have damaged the double socket (stopped using that charger now - never convinced it was up to scratch).

 

[Taylortwocities]

Manchester = rain
Have you had some? I have!

do you have any outdoor electrics? sockets, feeds to sheds etc. Any dampness will cause problems.

Also central heating systems. Make sure your boiler and all associated stuff is switched off.

 

[Northbeach]

Manchester = rain
Have you had some? I have!

do you have any outdoor electrics? sockets, feeds to sheds etc. Any dampness will cause problems.

Also central heating systems. Make sure your boiler and all associated stuff is switched off.

Yes, it has been a little wet of late

Garage feed - possible this could get damp (garage is on it's last legs but will be coming down in time. Outdoor light attached to garage also. The garage feed and boiler are both on separate circuits (with own mcb) and both of these are ok. Just inpected the double socket the aforementioned iPod plugs into - one of the socket points (lower left) looks a little scorched...possible perpetrator? Not sure how durable sockets are and what the fail rate is, but this does'nt look good. I have a new double socket I can replace it with.

 

[JohnD]

As well as looking for water (especially in outdoor lamps, sockets, pond equipment, or round the boiler and its pump) look for any nails or screws in walls, ceiling or floor that might have punctured a cable.

 

[Northbeach]

As well as looking for water (especially in outdoor lamps, sockets, pond equipment, or round the boiler and its pump) look for any nails or screws in walls, ceiling or floor that might have punctured a cable.

There are two sockets, two flori lights and a garage lamp on the outside - given it's state, entirely possible damp has affected the circuit. However, the garage circuit is working fine (I'm having to use the socket in there to extend to the fridge freezer in the kitchen - at least we have a working fridge!
Have taken out the socket with light scorch and replaced with new double...RCD still down. Will continue to check all the other sockets - after that, I've no idea where the issue lies!!!

 

[Luckyphil]

I`ve had problem with stupid things like Kettles being left in 1/2" of Water

When checking Sockets check to see if the Back of the Box is dry , I had a fault on a job the other Day . somebody had fed an Outside Light via a spur , And fed the Cable through the back without a drip bend on said Cable, The Rain was following the Cable down into the Backbox it was dripping !

Is the Immersion (if you have one ?) fed via the Ring Main , The Element can go down causing tripping.


Or get a Sparky in to test the RCD Properly - Marbo is`nt the rolls Royce of Consumer Units.

Lucky

 

[JohnD]

As we've alluded to, earth leakage faults are very often due to water.

If it is a true ring, then it is possible to narrow down where the fault lies, but it involves quite a lot of disconnection and reconnection, usually including inside the consumer unit.

If you want to make a start, I would recommend you draw a plan of the house, and sketch in the route that the circuit probably takes, it will run from the CU from socket to socket, eventually returning to the CU.

You need to identify the sockets which at each leg of the ring, are likely to be those connected direct to the CU, and also the one which is likely to be in the middle of the ring, furthest from the CU.

You will also need a multimeter, and to be very very careful in testing and retesting that the circuit is dead.

You might do better to start asking around friends and neighbours for their recommendations of a reliable local qualified electrician.

 

[Northbeach]

Hi folks - thanks for the replies.
There is another outdoor light on the back of the house (security sensor) - this is connected to the mains via an ordinary plug. Another possibility perhaps. Will check this socket as I'm checking all the others (quite old wiring do not that many sockets) - have replaced two already - One that loOked a little scorched and another that was cracked. House will need a require in the near future anyway.
Yes - doesn't look like the greatest CU, though relatively new.
Any chance the actual RCD is at fault or does that the fact the other circuits work make that unlikely?

Water/damp does seem likely. Kids will be wanting 'power' on their return from school...most likely ring for an electrician - can test for live (as I'm doing on every socket I test) but little else.

Thanks.

 

[Northbeach]

I`ve had problem with stupid things like Kettles being left in 1/2" of Water

When checking Sockets check to see if the Back of the Box is dry , I had a fault on a job the other Day . somebody had fed an Outside Light via a spur , And fed the Cable through the back without a drip bend on said Cable, The Rain was following the Cable down into the Backbox it was dripping !

Is the Immersion (if you have one ?) fed via the Ring Main , The Element can go down causing tripping.


Or get a Sparky in to test the RCD Properly - Marbo is`nt the rolls Royce of Consumer Units.

Lucky

No immersion heater, just combi boiler on its own circuit/mcb.

 

[flyingsparks]

When removing each socket front check that none of the wires have been pinched against the back box. Sometimes it's hard to see but a tiny bit of insulation can be damaged causing the rcd to trip. It's not NECCEARILLY a damp problem.

 

[Northbeach]

When removing each socket front check that none of the wires have been pinched against the back box. Sometimes it's hard to see but a tiny bit of insulation can be damaged causing the rcd to trip. It's not NECCEARILLY a damp problem.

Hi - not noticed anything untoward re nipped insulation yet, but will check thoroughly again. There was a leak in the overflow in the bath (just a little damp underneath, but there are no mains close by - fixed the leak this morning.
I was convinced it was the plug that had scorched, but havIng replaced that, still no luck.
I've found a socket (with a plug) behind some built in wardrobes - literally right next to this are two speed fit pipes coming frOm a shower in the adjoining bathroom - a: this shower is never used b: I have absolutely no idea what this plug is connected too (going off topic a bit there).

For any 'nics' is it reccomended to use heat shrink?

Many thanks.

 

[Luckyphil]

I`ve had problem with stupid things like Kettles being left in 1/2" of Water

When checking Sockets check to see if the Back of the Box is dry , I had a fault on a job the other Day . somebody had fed an Outside Light via a spur , And fed the Cable through the back without a drip bend on said Cable, The Rain was following the Cable down into the Backbox it was dripping !

Is the Immersion (if you have one ?) fed via the Ring Main , The Element can go down causing tripping.


Or get a Sparky in to test the RCD Properly - Marbo is`nt the rolls Royce of Consumer Units.

Lucky

No immersion heater, just combi boiler on its own circuit/mcb.

I`ve heard of Combi`s PCB`s causing E-Lkge problems occassionally , May be worth a shot disconnecting it - if its spurred off the Socket Circuit ?

Lucky