Bodge a pyro connection

[endecotp]

This is the light switch by my front door:

Both the pyro and the white flex go outside. The pyro is the original but at some point one of the conductors has got broken off inside this switch box, and the flex has been run in its place.

It’s not easy to get through the wall. The pyro takes a good route; the flex is a bodge. I’d like to revert to using the pyro but that means re-terminating it. There isn’t much slack but I could fit another box just for the termination.

I’m not going to buy a load of tools just for this one job. So my question: how difficult would it be to “bodge” a termination on this bit of pyro with no special tools? (I’ve seen guides about how to do it “properly”). I guess I do need the earth connection.

The other end is terminated in a round metal box on the outside wall and both conductors are intact; it has been partially sheltered by a fake burglar alarm box for some of the time and open to the elements at other times. I guess I should check insulation resistance.

Is this doomed?

 

[ericmark]

Near impossible, I would not even attempt with all the tools, I would find some one use to working with mineral insulated cables, (Pyro) it is specialist work, and even when I have been an electrician for 45 years, I would not attempt a one off, if I needed to wire a church then yes would buy the tools and practice a little and then do the job, but mineral cables are hygroscopic that is they absorb water, so slightest fault with the potting and it will go down.

 

[AndyPRK]

I was thinking you could add an architrave box above the switch to terminate it into. They have small holes though.

If the ends been exposed for years though, it's probably absorbed too much

 

[dannyboi2003]

Can you not remove the Pyro and run a new cable along the same route or is that not possible/ideal?

 

[endecotp]

Can you not remove the Pyro and run a new cable along the same route or is that not possible/ideal?

It’s an old stone wall. On the inside, I’d need to remove and then replace a lot of plasterboard; on the outside, I’d need to remove and replace pointing, from the top of a ladder. The new mortar would no doubt stand out like a sore thumb.

 

[dannyboi2003]

It’s an old stone wall. On the inside, I’d need to remove and then replace a lot of plasterboard; on the outside, I’d need to remove and replace pointing, from the top of a ladder. The new mortar would no doubt stand out like a sore thumb.

Hmm i had a feeling it wouldn't be that easy, what's the other end of the pyro like, is it still terminated and in good condition? If yes I would find a local electrician who can terminate pyro (it's not a DIY job) who can first test the cable to make sure it's still good and worth repairing then re-make the end at the switch. Given how much damage you'd need to make to replace the cable the cost of paying someone to repair it must be worthwhile.

 

[333rocky333]

Its unlikely to have absorbed much moisture , if any due to the pot and compound on the end of it, are you sure theres not enough protruding through the seal to get a small 2 amp connecter on it

 

[endecotp]

are you sure theres not enough protruding through the seal to get a small 2 amp connecter on it

I’ve not examined it very closely, however someone in the past has gone to some trouble to run the white flex so I have assumed it is terminally borked. But that’s a good point; I will have a good look tomorrow in daylight.

Anyway, I see no-one is suggesting that I should “have a go” at a DIY pyro termination!

 

[SUNRAY]

Should I

“have a go” at a DIY pyro termination!

No.
No.
No.
And finally no.

Having done a few pots and I do mean only a few, more than I can count on my fingers but not much more, I had occassion to shorten a damaged pyro without tools. I was lucky that the length was not critical and had several goes at the job.

Oh on top of it being very difficult the copper tends to have very sharp edges and received several cuts.

Never, NEVER, NEVER again.

 

[RF Lighting]

Don’t know if you’ve seen my guide to pyro termination in the DIYnot wiki?
https://www.diynot.com/wiki/Electrics:MICC

I wouldn’t recommend DIY pyro either! It’s a fairly tricky cable to terminate with the proper kit. It can be done without any special tools, but I definitely wouldn’t recommend anyone tries that on their first go!

Are you able to see any writing on the gland or pot seal? Something along the lines of 2L1.5 this will give us an idea if it’s metric or imperial pyro, the latter adding another extra little hurdle for you!

Where are you located? I really like rescuing old pyro when others suggest it needs replacing!

 

[endecotp]

Well that’s something I never want to do again...

I removed some plasterboard and pulled a string through the wall using the pyro. It was threaded between the stones and is obviously not very flexible. It took ages and lots of tugging from the top of a stepladder but I finally got a new cable in place!

 

[securespark]

Boo hiss, you've spoilt it now!