Repairing imperial mineral cable

[davesparks]

No idea , I do remember Pyrotenax's heatshrink pot/ seals but never used them.

I keep a few of the heatshrink seals for emergency, 1 size fits most, type repairs.

I got one of the wedge pot tools in a box of second hand tools a few years ago but have never used it or even found new wedge pots.

 

[7029 dave]

I keep a few of the heatshrink seals for emergency, 1 size fits most, type repairs.

I got one of the wedge pot tools in a box of second hand tools a few years ago but have never used it or even found new wedge pots.

Can you still buy them, struggled to find them got a pic to show other members if they haven't seen them before.

 

[davesparks]

Can you still buy them, struggled to find them got a pic to show other members if they haven't seen them before.

They aren't manufactured anymore.
I keep an eye out for new old stock appearing on ebay.

I've collected a stock of cable and fittings from various people clearing out their stores.

 

[Boonsy641]

Good, this clamp makes the earth connection to the copper cable and the circuit must not be energised without it fitted.


I can't make out the 3rd core for either of them.
Has anyone said what that thrid core is being used for?


It is very hard to make a repair if it is snapped off at the pot, but not always impossible.

Cutting back 2 feet is unnecessary, it will only need to be cut back enough to expose enough of the snapped off core to be able to join onto it.
Has anyone carried out any testing yet to see if the cable is in useable condition or not?


The only real risk is that the cable may have corroded due to chemicals in the plaster. But it looks like it is plastic coated MICC which has just had the last inch or two removed, you can see the orange outer sheath on one of them.
The sheath will have protected the buried cable from corrosion.

Hey Dave. Trying to attach further photo

They look like wedge pots rather than the usual screw on pots, were they ever used on metric cable or were they older than that?

hi dave struggling to get low resolution images attached due to size. Defo 3 core each cable physically counted hopefully attached will show. Please see right cable. If you zoom in you can see ehats left of small cable. Electrician that came around said that if was to reterminate then the cables may be brittle in which case may not be able to reterminate at all in which case it defo would mean rewiring. At the moment he says the cable that broke is not live but is the common core that goes to next light in the loop. It connects to light switch and feeds of the live that is already there. He says best bet is to run a new twin and earth from the circuit breaker to the light that isn’t working but that would mean conduit across ceiling as in these flats the ceiling is concrete. I really would like to reterminate the pyro but worried about it being brittle as he says and making it worse

 

[Boonsy641]

They look like wedge pots rather than the usual screw on pots, were they ever used on metric cable or were they older than that?

Dave please see pictures

 

[littlespark]

For the photos, what I do when I take a photo with my phone is to screenshot it, then crop the screenshot down to just the original photo.
On my iPhone, that brings the image size just low enough for the forum to accept.

Do you have a photo looking up into the seal side of the pot, showing where the core is broken?

I still think you might get enough of a stump of copper for a very small connector to fit on…. Even the Ideal push fit type, rather than a block connector.

 

[Boonsy641]

For the photos, what I do when I take a photo with my phone is to screenshot it, then crop the screenshot down to just the original photo.
On my iPhone, that brings the image size just low enough for the forum to accept.

Do you have a photo looking up into the seal side of the pot, showing where the core is broken?

I still think you might get enough of a stump of copper for a very small connector to fit on…. Even the Ideal push fit type, rather than a block connector.

Thanks. That works. Please see. Just see the stump

 

[Boonsy641]

For the photos, what I do when I take a photo with my phone is to screenshot it, then crop the screenshot down to just the original photo.
On my iPhone, that brings the image size just low enough for the forum to accept.

Do you have a photo looking up into the seal side of the pot, showing where the core is broken?

I still think you might get enough of a stump of copper for a very small connector to fit on…. Even the Ideal push fit type, rather than a block connector.

Can you recommend a connector? I’ll try it myself I think. Many thanks

 

[davesparks]

Defo 3 core each cable physically counted hopefully attached will show. Please see right cable. If you zoom in you can see ehats left of small cable.

Yes I can see it now, that is definately a challenge to repair but I see no reason why it would not be possible to repair that with relatively little further damage to the wall.

Electrician that came around said that if was to reterminate then the cables may be brittle in which case may not be able to reterminate at all in which case it defo would mean rewiring.

I very much doubt that the cable has become brittle, without outside influences causing it copper doesn't just degrade and become brittle.

At the moment he says the cable that broke is not live but is the common core that goes to next light in the loop.

OK, that makes a bit more sense now.


I think you have 2 possible options here.

1 repair the existing cable

2 repurpose the switched live (marked yellow) as a permanent live and then fit a wireless switch with a reviver at the light to replace the switched live. The wireless switch may have to go on a surface box mounted over the existing switch position.

 

[davesparks]

Can you recommend a connector? I’ll try it myself I think. Many thanks

The only connection you could make onto that is by, with great care, cutting the plastic stub back and soldering then heat-shrinking.

There's no mechanical connector I can think of that will make a good connection to that tiny stub

 

[ipf]

If there isn't enough cable to repair, take the switch up 6 inches, new box with knockouts, or as existing with earth clamps fitted, strip back and re terminate.
Need a decent, experienced spark, though.
High switch, but what's the cost?

 

[7029 dave]

How the hell did that 3rd core snap off

 

[7029 dave]

If there isn't enough cable to repair, take the switch up 6 inches, new box with knockouts, or as existing with earth clamps fitted, strip back and re terminate.
Need a decent, experienced spark, though.
High switch, but what's the cost?

With Gland couplers and bush would make it a tad lower

 

[nicebutdim]

I haven’t made pyro off since my AM2 circ 1999 but I’m sure I still could with little issue.

I know this is not in the exam anymore, but is it still taught at college?

Indeed it is, although few will ever get much experience of using it.

 

[Boonsy641]

Yes I can see it now, that is definately a challenge to repair but I see no reason why it would not be possible to repair that with relatively little further damage to the wall.


I very much doubt that the cable has become brittle, without outside influences causing it copper doesn't just degrade and become brittle.

OK, that makes a bit more sense now.


I think you have 2 possible options here.

1 repair the existing cable

2 repurpose the switched live (marked yellow) as a permanent live and then fit a wireless switch with a reviver at the light to replace the switched live. The wireless switch may have to go on a surface box mounted over the existing switch position.

Dave. Can you recommend a wireless switch. If repurposing the yellow cable to permanent live then that would provide power to bathroom and bedroom that is currently in darkness. Is that right? Forgive my naïve Rss but how would the witless switch be powered? And you mean mounting witless switch over the top of normal switch? Is this something an electrician would find challenging or easy? Many thanks. Really appreciate your help on this I truly do

 

[Boonsy641]

How the hell did that 3rd core snap off

I have my doubts but initial electrician came round due to flickering light and tightened cables but before he did so he opened a few of the light switches and on this one when he opened it he said the cable easily came away.

 

[Boonsy641]

If there isn't enough cable to repair, take the switch up 6 inches, new box with knockouts, or as existing with earth clamps fitted, strip back and re terminate.
Need a decent, experienced spark, though.
High switch, but what's the cost?

My issue it seems is getting someone who could do this. It’s totally beyond the electricians I have had around. (So far 3). They have suggested a rewrite and then trunking or lowering ceilings!! I am absolutely dumbstruck that a single core of a cable is broken and I have been told it could abe a rewire running into the thousands. I know I don’t know electrics but I can’t understand why this cannot be fixed. Are any of you guys available to fix this please. Or recommend someone who can? Last electrician came around and I used all your comments and he went quiet. I feel he expected me just to accept a rewire. Thanks everyone. You are the light in a dark bathroom and 2nd bedroom!!

 

[westward10]

As is #90 this can be done. Carefully cutting the stub back with a razor blade or very fine file then snap it away and solder, someone who has patience and a deft hand.

 

[davesparks]

I know I don’t know electrics but I can’t understand why this cannot be fixed.

This type of cable has fallen out of common use, it can be time consuming to work with and the skills needed to fix it are rarely found within the domestic sector. So most electrician's you find doing domestic work either don't want to work with it, don't know how to work with it or some won't even recognise what it is.

Are any of you guys available to fix this please.

Depends how long you can wait! My other half is in Stevenage so I'm often in the area but I am fully booked now for a few weeks.

 

[Boonsy641]

This type of cable has fallen out of common use, it can be time consuming to work with and the skills needed to fix it are rarely found within the domestic sector. So most electrician's you find doing domestic work either don't want to work with it, don't know how to work with it or some won't even recognise what it is.



Depends how long you can wait! My other half is in Stevenage so I'm often in the area but I am fully booked now for a few weeks.

All the good one are fully booked is the rule. It just says to me that those fully booked are worthwaiting for. Sorry to ask and I am humble asking. How confident are you that you can fix it ?(sorry Dave. Have to ask) hope you don’t mind. Ime in Hitchin by the way