Electric sockets not working but MCB not tripped

[jimbodicko]

Hi - hope someone can help.

The upstairs socket have stopped working, yet the MCB has not tripped in the CU. I have tried unplugging everything and turning off/on again, but no joy. It went in the middle of the night, so it doesn't seem related to anything that was being plugged in at the time. It did do the same earlier in the day yesterday (and I'm pretty sure nothing was happening at the time to prompt it - i just noticed when i went to turn the tv on and it didnt work) and i turned the MCB off/on again and it worked fine.

What could it be - a loose connection? Dodgy MCB?

Possibly related - there used to be one socket upstairs (the same one that the tv is plugged into) that would occasionally trip the MCB. Last time that happened was at least over a year ago though.

fyi - it's a modern house - only 2.5 years old.

Help!

Many thanks,
James

 

[wingcoax]

Make sure the power is off, then check all upstairs sockets starting with the telly one for loose connections. If nothing found is the upstairs fed from downstairs ring? check all sockets for loose connections. With a fairly new build they should be ok but it could have been a friday afternoon job.(must finish by 3 o'clock)

 

[jimbodicko]

Knowing the builders a little - not just a Friday afternoon, but Friday morning and Thursday afternoon as well!

It is that socket as I unwired and rewired it and it worked - until i pushed it back into the wall and it went off again. Will fiddle again in the morning.....

Thanks for your help - much appreciated.

 

[ricicle]

Is this a ring final circuit ?

 

[ban-all-sheds]

It is that socket as I unwired and rewired it and it worked - until i pushed it back into the wall and it went off again.

If you did that and then it did that then whatever the fault is it is entirely of your making - nothing to do with the original builder/electrician.

Is it definitely an MCB that's tripping, not an RCB or RCBO?

 

[ricicle]

Socket or sockets ?

 

[jimbodicko]

ban-all-sheds: It was already not working before i ever unwired/rewired it - I was just trying to make the connection better.

well, it's a double socket, if that answers ricicle?

 

[jimbodicko]

PS: I don't know if it's a, RCB or RCBO: it says MCB B32 SFMBB32 on it, if that helps? It's a MARBO CU. I'm afraid I don't know what a ring final circuit is: only that its the circuit controlled by the fuse in the CU titled 'upstairs sockets'!

it's not actually tripping out when i turn it back on - I get a brief moment of power (I'm using a lamp in another socket as a tester, so I can tell) and then it goes off again. Twice the lamp has stayed on and I think i've cracked it so I've turned off the power and after i screw the socket back into the wall and turn the power back on, i've got the brief moment of power then nothing (but still no actual trip of the MCB).

 

[martinxxxxxx]

I can tell from the information that you have supplied that it is not wired correctly.

If it is supplied from a 32A MCB using 2.5 te cable it should be ring cct and therefore fault on one socket should not affect the lamp on an adjacent socket.

Get who ever put it in back to sort it out, ask them for a certificate which they shouldhave done in the first place

Martin

Just a thought I have overlooked the dodgy MCB issue. Try flicking it off and on several times in succession and see if this improves things. If not get it tested and replace professionally.

 

[ELZ4742]

martin beat me to it....

a ring is exactly what is says in the tin. starts at the mcb goes to each socket then returns to the mcb on another cable so in effect, if you have a problem on one leg, it should still feed on the other (which is actually a major flaw of such a circuit due to the fact you could end up feeding a 2.5 radial on a 32a breaker)

there is the possibility that the adjacent socket could be a spur from your 'problem' socket how many cables are in there?

 

[ban-all-sheds]

ban-all-sheds: It was already not working before i ever unwired/rewired it - I was just trying to make the connection better.

My apologies - I misunderstood what you'd done.

So it works OK if it's not fixed back in place, but when it is it pretty soon trips the MCB?

Unlikely to be a faulty MCB then.

Where is the socket? Do you have children or small animals of whom you are fond?

Can people be trusted not to jam their fingers into the back of the socket if you leave it loose for long enough to be sure that everything works fine with it like that?

Could you live without the socket for a while - replace it with some 30A choc-block under a blanking plate?

Have you had a good look at the conductors in the socket?

Any chance of some good quality closeup photos of the wiring there?

 

[scousespark]

It is that socket as I unwired and rewired it and it worked - until i pushed it back into the wall and it went off again. Will fiddle again in the morning.....

I would recommend you call an electrician to get the circuit checked. Try going back to your builder. He may sort this out for you.

Eletricity is not something you should fiddle with

 

[jimbodicko]

Such a lot of helpful people - thank you all!

Scousespark - you're right, I'm goign to get my brother-in-law, who's an electrician to come round tomorrow night. The builders weren't actually mine - we just bought a new build from a developer and I don't have details for the builder. The reason I made negative comments about the spark was that one of the light switches and one of the phone sockets have needed rewiring as they were loose, so they have 'previous', so to speak! For reasons too long to explain here, going to the developer is very much at the bottom of my list of options.

Ban all Sheds: "So it works OK if it's not fixed back in place, but when it is it pretty soon trips the MCB?" - no, the MCB never trips - the sockets just stop working when i push the socket back into place. Sadly, i then have to go back to scratch in terms of wiring so it works again - it's not just a case of unscrewing the socket from the wall and the sockets work again(far from it - it takes many tries). Almost as if the wires need to be bent at a particular angle!

ELZ4742 - There are two thick grey cables, each with three wires coming from them, plus there's an extra earth wire.

I do need to use the sockets and I have a 15 month old, so will be looking forward to the brother-in-law fixing it! Don't have a pic yet, but will try to upload one later this evening.

Many thanks to all.
James

 

[ban-all-sheds]

Ban all Sheds: "So it works OK if it's not fixed back in place, but when it is it pretty soon trips the MCB?" - no, the MCB never trips - the sockets just stop working when i push the socket back into place.

Yes - you said that in the first post.

Is be doin good at this reedin lark.

 

[jimbodicko]

Solved!

After speaking with my brother-in-law I took the front casing off the CU with a view to swapping the MCBs to see if the fault followed the MCB - before I swapped it I tried tightening the screws and one was loose. Tightened that and all working fine now!

Thanks to all for the help.