Disconnecting electric shower

[ss]

At some point in the next couple of months I will be disconnecting the electric shower and replacing with a shower to be combi fed. I dont see me converting back to electric but will keep the cable in situ (in the ceiling void, and labelled) Am I best to terminate this in a junction box?

I assume best practice would be to also disconnect at the MCB but not keen to touch that or is it easy enough to do?

So it would just be switched off and terminated in the ceiling void and later on once I have a couple of other small jobs needing done call in an electrician to disconnect.

[Nick]

Definitely disconnect from the MCB. Turn the supply off & disconnect L, N & E. Tape all together and label. Likewise at the shower end. Simple enough job.

[Bill Wright]

Or remove the appropriate fuse and make sure everything is labelled.

Bill

[Tim Watts]

If you are going to be absolute, any unused conductors should be earthed.

Anyway, another way to do this would be to disconnect at the isolator (pull cord or wall switch) if there is one.

[ss]

There is a wall switch external to the shower room, If i disconnct at the MCB and the shower end should this be necessary?

I dont quite understand "any unused conductors should be earthed" Laymans terms required, if both ends are disconnected then why should they be earthed.

[spuorgelgoog]

It is possible they may become live through accident (eg rubbing against a bus bar or terminal in the consumer unit) or incompetence (someome mistakes it for another wire).

If the unused wires are earthed then the fuse/circuit breaker will operate immediately. If they're not earthed then they may remain live for some time, until someone touches them, fzzzzt.

Owain

[philipuk]

I would guess this would be to mitigate the chance of them being accidentally and incorrectly reconnected after future electrical work.

[Graham.]

I don't think you have to in the context of domestic wiring. Perhaps Tim was alluding to this:

[Tim Watts]

Well - it's debatable with a fully disconnected cable and depends who it is disconnected. Unused cores in a live cable would be connected to the CPC (that's an IET Wiring Reg).

Certainly connect all the cores at both ends together in case someone accidentally reconnects the cable at source (because the conductors are all strapped to the CPC at the far end, breaker trips).

But if you were isolating it at the isolator switch, which is fine, my inclination would be to bond all cores on the outgoing (shower) cable to the earth terminal in the isolator box. Leave the incoming (cable to CU) connected to the isolator. Strap the cores at the far end together.

Now it is impossible for that cable to accidentally become live, and you will not have loose conductors in the backbox that may touch a live source.

That is unless you can remove the outgoing cable from the isolator far enough that reconnection is impossible.

[Tim Watts]

Partly. But my last recent reply has my full thinking on this...

[Graham.]

On a different tack, there's an interesting socket in that film at

4:31 I saw that film many times on BBC2 in the '70s, but never noticed it.

Here's a still

And I've found a plug that fits it

For some reason I had to use a Facebook login to post there. I hate the web!

[Andy Burns]

Just realised that this chap

who does adenoidal teardowns of old or dodgy electrical items is Mr Flameport ...