Smoking junction box

[toasty]

Mate of mine called me the other day, his mum's house upstairs lights had been flickering occasionally, apparently for the last 5 or so years.

Not sure why he'd not mentioned it before, but anyway!

He phoned me because they'd finally failed and all of the upstairs light now wouldn't work at all.

I popped round there and had a good dig around, after a bit of trouble shooting realised that there must be a junction box under the floor somewhere, and from what I could see from the ceiling roses this junction box had a broken live in it.

We found it under the floor at the top of the stairs (the cable out from the consumer unit was tee'd off there to feed an understairs cupboard) and when we pulled up the floor boards, the junction box was actually smoking and on removing the lid, the wires going to the live terminal were actually glowing red!!!


I'm not actually an electrician, so I don't see this sort of thing very often, but I was quite shocked at the amount of heat this was producing and the heat damage it had caused to the cabling.

It's all fixed up now - probably the way it should have been done in the first place. I pulled the cables down in to the understairs cupboard and made all the connections in a ceiling rose there, thus removing the need for the junction box (the old understairs light fitting was just a battenholder light fitting, so this wouldn't have been possible)

Just thought I'd share with everyone here. There is a reason why the regs don't allow hidden JBs and there is a reason why we need to make sure terminations are made well and sufficiently tight.

This was just a 6amp lighting circuit with maybe 500 watts ~ 2amps of load on it. Imagine what a 10Kw electric shower could do!!

I must admit, I think his mum realised just how close she might have been to having a house fire, with all the dust and debris under the floor and the smoking junction box there was a definite risk of fire there.

 

[plugwash]

mind you accessible for inspection doesn't mean faults will nessacerally be noticed.

what this imo really says is you shouldn't ignore signs of bad contact!

also note that smoke doesn't nessacerally mean your anywhere near fire, a lot of stuff will smoke at far lower temperatures than it will burn at.

 

[bathjobby]

Oh thats all right then. There you go toasty, there wasn't a problem after all !

 

[big-all]

shurely if the wire was glowing red hot all surrounding wire [ and maybe beyond] will be dammaged!!!!!

for piece off mind i would want the wiring and possibly the whole electrics checked

 

[securespark]

And how old is this junction box? Do the parents know it is smoking?

 

[toasty]

And how old is this junction box? Do the parents know it is smoking?

I would have said the junction box was 50 or so years old, and his mum was there at the time, she looked pretty shocked at the general smoking etc...!

She reckons her Dad must have fitted it about 20 years ago (he's sadly dead now) but I reckon it must have been a second hand one at the time, it's certainly older than 20 years old - looked like bakelite to me.