Advice On Rewire Of Lighting Circuit

[Master Mech]

I have just had some work carried our to rewire a lighting circuit in my house due to it having no earthing.

The lighting circuit is the original lighting circuit that was installed when the house was built in the 50's which was ran in steel conduit.

We now want to fit metal accessories but obviously require earthing for this to be safe so a rewire of this circuit is required & to be honest has been way overdue for replacement anyway.

Like most people I did not fancy chasing all the walls out to install new cables so asked the electrician if the steel conduit already plastered into the walls could be used saving the need to chase the walls out & redecoration.

He said that would not be an issue after looking over the installation as there would be enough room for the new cabling to be fed down the old conduit which was great news.

When he came to install the new cabling here found that he could not install the twin & earth cabling with the sheath attached as there was not enough room inside the conduit.

His solution was to strip the sheath from the twin & earth cabling and then wrap all the individual wires together in electrical insulation tape.

Removing the sheath created the room required to be able to feed the cables down the existing conduit.

Where the conduit ends in the loft space he left the sheath on the cables & the ran them to a junction box.

Here are some pictures of the junction box in the loft space & the tops of where the conduit for the switch drops end.

The same lighting circuit also covers not only the upstairs bedrooms but the landing, hallway & dining room lighting so cables needed to be ran under the landing floor boards & junction boxes installed.

Here are some pictures of the junction boxes under the landing floorboards.

So my question is are there any issues with how this work has been carried out?

I am probably making a mountain out of a mole hill but I would really appreciate your input.

Many thanks

Adam

 

[westward10]

PVC T&E and PVC singles are both manufactured to BS6004 and it would be assumed the insulation of the copper conductor is of an equivalent. If the sheath of the T&E is removed then it should be correctly contained as with singles after all the sheath is removed at accessories and within distribution boards.

 

[HappyHippyDad]

I agree that on a rewire junction boxes should be avoided, but sometimes we do use them when it's going to make live MUCH easier. That surface box is an odd choice but if it is in the loft then they do not need to be maintenance free, I have seen far far worse, at least there is no basic insulation showing and he has cable tied them to keep in place.

I cant comment on twin and earth being stripped back and put in metal conduit as I don't know if it's any different to singles, although from James's post it looks like it is. The metal conduit will certainly give greater protection than a piece of plastic. I don't like the sharp edges on it though, some heat shrink would have been better along with something to soften those edges. Plus it needs to be earthed, but perhaps it is.

 

[Master Mech]

The consumer unit is under the stairs & original lighting circuit comes out of the top of the consumer unit into the cavity inside the stairs making its way to under the floorboards of the landing.

All the cables going to & from the consumer unit are plastered into the wall & if I can avoid it I asked if it was possible to not chase the wall out. As you can tell I am not a fan of decorating

The solution he came up with was to drill a hole through the wall the consumer unit is mounted on which is an external wall & run a cable from the consumer unit in conduit on the outside of the house up to the loft.

From there he has split that feed in the loft for all the lights in the three bedrooms upstairs.

To be able to rewire the landing, hallway & dining room lights he used the switch drop for the landing light that also drops all the way under the landing floorboards. Then placed junction boxes under the landing floor boards to be able to supply the dining room & hallway lights.

I hope this all makes sense.

Thanks guys, that was one of my jobs. Anyway such a device (metal containment) for singles/T&E should technically be earthed which it is not. As @Wilko points out the JBs should be MF so replacing them with wago MF boxes would sort that. In order to stop thermal cycling and vibration causing any harm the JB should be affixed to the joists which Wago boxes have provision for so that would meet that criteria. I normally sleeve the three core as well. Essentially I see nothing too bad here, it could be improved but I do wonder why the OP does/did not have enough confidence in the spark in question to not go around after him and check his work. Any comments OP? I have once or twice been held to account by customers questioning methods of installation which comply with regs and it can be very difficult for the installer where there is no merit in such a lack of confidence. However there is some merit in the OP, in this case, but clearly the installation has been left a lot safer than when he started looking on the bright side.

I did question the electrician about some other work he carried out which did not end very well. He got very offended that I was questioning his work & that I did not trust him. He took it very personally.

I have another thread here about a radial he installed along with this circuit & when I asked him why he installed a 32 amp MCB on a 4mm2 cable that he ran in conduit with other cables he said it was fine & posed no risk.

I told him it did not meet the wiring regulations but apparently he has never had an issue in his years of experience & they were only guidelines.

 

[Master Mech]

Plus it needs to be earthed, but perhaps it is.

What's the best way to know if it's earthed?

Right now its just a piece of metal conduit plastered into the wall. It is not connected to the back box it drops to or anything on the other end in the loft.

 

[Pete999]

Thanks guys, that was one of my jobs. Anyway such a device (metal containment) for singles/T&E should technically be earthed which it is not. As @Wilko points out the JBs should be MF so replacing them with wago MF boxes would sort that. In order to stop thermal cycling and vibration causing any harm the JB should be affixed to the joists which Wago boxes have provision for so that would meet that criteria. I normally sleeve the three core as well. Essentially I see nothing too bad here, it could be improved but I do wonder why the OP does/did not have enough confidence in the spark in question to not go around after him and check his work. Any comments OP? I have once or twice been held to account by customers questioning methods of installation which comply with regs and it can be very difficult for the installer where there is no merit in such a lack of confidence. However there is some merit in the OP, in this case, but clearly the installation has been left a lot safer than when he started looking on the bright side.

"you see nothing to bad" what? stripping twin and earth and threading the cores down a conduit is not bad? it's downright disgraceful workmanship.

 

[James]

PVC T&E and PVC singles are both manufactured to BS6004 and it would be assumed the insulation of the copper conductor is of an equivalent. If the sheath of the T&E is removed then it should be correctly contained as with singles after all the sheath is removed at accessories and within distribution boards.

They both meet the requirements of BS6004, for abrasion resistance tests, they are tested as a complete product, inner cores are suitable for being contained within an enclosure.
However there is no testing or approval for taking a cable apart and drawing its unprotected inner cores through conduit.

 

[Vortigern]

I don't see it Pete, singles are drawn through conduit all the time what is different in this case. While I understand you feel it is disgraceful, and maybe you are right, what is wrong with it? How does it not comply or present a danger to the client? What reg would you quote in an EICR for instance. I eschew going in too hard on another electrician especially in a public place. I always feel the other side should be present to defend themselves. Besides which it is tantamount to libellous in describing work in such a way and may have no defence where it cannot be proven.

 

[7029 dave]

Well for starters 1mm t&e should have been used, also why 2 cables down could of used 1mm 3 core and earth.

 

[westward10]

Whether he should have stripped the cables back is debatable, what isn't debatable is that once he realised he could not get the cables down the tubes was to stop and review the situation. As previously stated this would have been my first port of call to see if it was feasible. Conductors are clearly exposed outside of the tube and wrapped with tape, this is not acceptable.

 

[Wilko]

As @Wilko points out the JBs should be MF so replacing them with wago MF boxes would sort that.

The connector 2273 seems to have been popular and it will need an adapter for the standard Maintenance Free box (I don’t use these connectors for that reason ).

 

[westward10]

I suppose the most not obvious solution as it isn't used too much now was to use 6181Y they would have flown down the tube.

 

[Pete999]

I don't see it Pete, singles are drawn through conduit all the time what is different in this case. While I understand you feel it is disgraceful, and maybe you are right, what is wrong with it? How does it not comply or present a danger to the client? What reg would you quote in an EICR for instance. I eschew going in too hard on another electrician especially in a public place. I always feel the other side should be present to defend themselves. Besides which it is tantamount to libellous in describing work in such a way and may have no defence where it cannot be proven.

Simple really mate, whilst I can't point you to any hard and fast written regulations, the simple facts are the cores of a multi core cable are not designed to be use without the Mechanical protection provided by the outer sheathing,
Singles designed for installing in conduit or trunking are and are installed as such , I agree that twin and earth is stripped down to the individual cores are visible in switches etc, but that is an enclosure in it's own right, it's the same as saying I can't get this twin and earth through this hole, "I know Ill strip the sheathing off it will fit then.
I stand by what I said earlier the OP described the install in his house is disgraceful.

 

[ferg]

It looks a bit rushed / rough and there are undoubtedly bits that could and should have been done differently.

However I'd be struggling to justify paying someone else to rip it out and re-do it. I think that is a reasonable threshold for the difference between a bit rough and downright dangerous.

 

[Mike Johnson]

Well this has certainly polarised opinions, will be interesting when and if Doncaster cables get back to me.

 

[Dustydazzler]

I certainly wouldn’t advocate pulling it all out n starting agai.
I rewired my parents house 20 years ago using the original split tube , but managed to get a twin n earth all the way down it fully sheathed all the way.
if I couldn’t get it down the tube sheathed I would have chopped it out & put some 20mm pvc conduit instead. But that’s just me ...