Extend wire, how?

[t87699]

Wire for immersion heater, coming out of concrete wall not long enough to reach the switch.

How can I add a 1" extension in order to connect this wire to the switch, and still be safe?
I'm looking for something small that would fit in the area in the concrete wall, behind the switch.

The insulation on the wires was damaged when they got very hot, and it shorted.


Thanks

 

[Deleted account]

Relocate the back box Further down the wall.

chase it out move it down. No need to extend.

you’ve got to chase out anyway to get to cables so just do a little more.

 

[t87699]

OK, no way to extend it in the box? Perhaps with a small junction box?

Thank you

 

[telectrix]

first i would dig out tha back box and see if i could pull some slack. you'd need to get further back along the cable to find undamaged conductors and insulation. failing which, see which way the cable runs, (from below is usual ) and dig it out further down. refit backbox and new switch lower ( or higher if cable comes from above )

 

[t87699]

OK

Thank you for the help

 

[telectrix]

OK, no way to extend it in the box? Perhaps with a small junction box?

Thank you

no way at all. the damage could be 6" or more along the cable.

and that back box looks like it's way too shallow. cables squashed probably was cause of damage.

 

[Lucien Nunes]

Am I seeing twisted and taped joints to what looks like butyl flex? What was actually fitted to that box previously, if anything? Did someone install too shallow a back-box, discover that no accessory could be fitted, twist on the cable from the immersion and walk away?

As pointed out above, heat conducted along the copper may have degraded the insulation beyond the point at which it looks burnt, so a careful strip-back is needed.

 

[t87699]

OK Thanks

 

[Deleted account]

Lucien has picked up on a good point there.

that backbox does look way too shallow. A deeper back box will help heat dissipation and stop the conductors getting squished together.


note: “squished“ is part of my electrical technical Terminology?

 

[Lucien Nunes]

It was Tel who pointed out the box depth. Squished is also part of my terminology, it's half-way between squashed and squidged.

 

[Deleted account]

It was Tel who pointed out the box depth. Squished is also part of my terminology, it's half-way between squashed and squidged.

Thanks lucien

sorry tell.

 

[t87699]

I could always dig out the back box, in the concrete wall...

 

[Deleted account]

I could always dig out the back box, in the concrete wall...

Good idea!

then fit a deeper backbox further down.

 

[telectrix]

TBH, for what's involved, I'd seriously recommend getting a qualified electrician in. not a great cost. you've luckily avoided 1 fire. don't risk a 2nd. also, you mentioned concrete. if so, could you be weakening the building structure by chiselling deeper? a surface mount might be mor appropriate.

 

[freddo]

I'm not seeing a CPC, is this a steel conduit installation?

You need an electrician by the way. That twisted join is appallingly dangerous.