Downstairs sockets tripping

[trebarwith33]

Hey all, we bought a 2 bed Victorian terrace almost a year ago and last night the electric suddenly cut out.


We were in the kitchen cooking so had the lights on and whatever else is plugged in/on standby around the house at the time (internet, sky box, fridge freezer, boiler etc). So hardly any load at the time it tripped (btw, the oven and hob are gas and not even connected to electric)

I flicked the mains trip switch and it immediately tripped again. I then removed each fuse (very old fuse box it seems) one by one and narrowed the problem down to the one labelled “Dining room”.

We’d already discovered a few months ago that “Dining room” actually means the entire downstairs – so front room, dining room and kitchen (a total of 8 double sockets). That’s not right is it?

We then unplugged and turned off all sockets downstairs and tried the mains circuit breaker again but it still trips.

Possible Cause 1: a few months back we had a problem with rats under the suspended floor. No idea how they are getting in, pest control suggested they are most likely coming in from either side (terrace house) as no signs of entry on our property. (The neighbours smoke and we can tell this inside our place, so there must be gaps under the floors somewhere!) We put down poison and definitely killed a few and haven’t heard anything since. When poking around under the floorboards we did spot a few gnawed cables but nothing too bad, mostly just in the outer insulation but in a couple of spots there is a mm or 2 of exposed copper in one of the inner wires. In the time we’ve been hearing things under the floors the gnawing of cables doesn’t seem to have gotten any worse – although this is only in the spots we can easily check. So how likely is that a rat has chewed through something and caused something to short out?


Possible Cause 2: We recently fitted a new light in the bathroom. It was an easy job just unscrewing the 3 wires from the old unit and screwing into the new unit (triple checking the wires were correct and all wiring was inside the sealed box within the light unit). It all worked fine so that’s great, I think. The bathroom lights are on the same circuit as all the downstairs lights which is a separate circuit to the faulty sockets circuit. Is it still possible that my DIY light replacement could be the cause of the trip even though it’s on a separate circuit? I’ve already tried pulling the fuse on the downstairs light circuit and reconnecting the fuse for the faulty sockets but it still trips.

I should mention that the morning we fitted the light we went out all day, came home in the evening and noticed the power was out (can’t work out if it was already out when we walked in, or it tripped when we started turning things on – only indicator was the fridge was still very cold – I have a thermometer in there, so can’t have been out for long). On this occasion I flicked the trip switch and it all came back on fine and has been working for the past 4 days now.


So despite the known issue of the rats gnawing cables (it’s entirely possible they are back despite us not hearing a peep from them), I think it’s too big of a coincidence that the problems started after installing the new light fitting. What do you guys think? Is it worth me removing the new bathroom light and seeing if the other circuit still trips?

Thanks for reading

 

[Risteard]

Have you tried tieing their laces?

 

[Taylortwocities]

The little critters will get in any and everywhere, if indeed that is the problem.

This sort of problem could be a fault with something attached (heating valves, leaking shower, faulty freezer, external light, socket, etc etc)
or it could be a wiring fault casued by nibblers or something else.

Once everyting has been unplugged or isolated (and that means both live and neutral) its not easy to spot this sort of thing by just looking, you'll need an electrician who knows what he is doing to come and use an insulation resistance tester to try and identify where the problem might be located.

 

[trebarwith33]

Thanks, we will definitely be calling out an electrician, probably for a complete rewire which we were expecting to have to do at some point. But maybe not quite so soon.

 

[Taylortwocities]

Let us know if you get a result!

 

[JohnW2]

The little critters will get in any and everywhere, if indeed that is the problem.

Indeed, the can and do - and if they do, this is the sort of thing they can do:

.. that was found by inspection (pulling up floorboards), undertaken because the presence of the visitors was known, before it had 'shown itself' electrically, and prior IR testing had found nothing wrong with circuit.

Kind Regards, John

 

[trebarwith33]

An update!

We've been lazy/busy/not that bothered about the lack of electric sockets downstairs (we have an extension lead from upstairs for the fridge and TV) so have only just called out an electrician - it was probably the need for some working sockets for the Christmas tree lights that finally did it

Over the past few months we would occasionally plug the fuse in and it would trip each time.

Anyway, electrician turns up and first thing he does is put fuse back in and everything works! He then proceeds to test all sockets and can not find any problems. We then plug in and switch on everything we can find to put it under a bit of load but no problems at all.

What's weird is when we moved in a year ago we noticed one socket wasn't working so decided to never use it (and we haven't since), but during testing he said this one WAS working now. I had a brand new socket we were going to replace another old looking socket with so I asked him to swap out the dodgy one with the new one and that was that, been working for the past week or so.

He did tell me off and say if it happens again to call them ASAP as they will be able to find the fault much easier when the fault is repeatable.
He didn't have any answers as to what might have caused the problem so what do you guys think?

 

[deadshort]

Water ingress into the wiring or washing machine leaking ? Or, it was only a small rat, that was not capable of taking the 32a load in its teeth ?And it's now fried ……clearing the fault !

Regards,

DS

 

[Iggifer]

Yea the fault must have cleared itself. I'm with DS, water ingress/damp is your prime suspect.

We haven't had much rain recently (well, here at least) so it may well have dried out.

 

[trebarwith33]

An update...
Well it has been fine for months until a few weeks back when it did it again and wouldn't come back on.
Electrician identified a faulty cable between 2 sockets on a ring circuit. He disconnected the cable from both sockets giving us 2 radial circuits? (can't remember exactly what he said) so at least all our sockets will work until we can rip up the floor where the faulty cable is.

And yep, water ingress is the likely cause since the faulty cable runs through the bathroom, under the bath (is that safe??) where there are signs of a previous leak - all absolutely bone dry right now though which is odd.

At some point we are planning to re-do the bathroom anyway so we will get the cable replaced and the ring circuit reconnected.