Advice On Rewire Of Lighting Circuit

Master Mech · Nov 15, 2020

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

Master Mech · Nov 16, 2020

7029 dave said:
Well for starters 1mm t&e should have been used, also why 2 cables down could of used 1mm 3 core and earth.

The drop that has the three core with the twin & earth cable feeds two switches. A 2 gang switch & 1 gang switch.

When the house was built they decided to use one drop for both rooms.

The only insulation the CPC's have is the electrical tape that is holding all the wires together.

Pretty Mouth · Nov 16, 2020

It seems to me that the problems with this install are a result of the spark trying to keep the OP happy, by avoiding damage to the decor. Had he been able to cut in chases and new boxes, there would have been no need for the junctions in the building voids, or for stripping the sheath from the T+E.

7029 dave · Nov 16, 2020

Master Mech said:
The drop that has the three core with the twin & earth cable feeds two switches. A 2 gang switch & 1 gang switch.

When the house was built they decided to use one drop for both rooms.

The only insulation the CPC's have is the electrical tape that is holding all the wires together.

Okay understand that, 1.5mm cable was a bad choice, 1mm cable's might have gone down together with a bit of lubricate such as fairy liquid thats what I have used, failing that chase out the other switch drop, or surface mini trunking.

Dustydazzler · Nov 16, 2020

Pretty Mouth said:
It seems to me that the problems with this install are a result of the spark trying to keep the OP happy, by avoiding damage to the decor. Had he been able to cut in chases and new boxes, there would have been no need for the junctions in the building voids, or for stripping the sheath from the T+E.

quentic switches would have been the best option

westward10 · Nov 16, 2020

6181Y.

7029 dave · Nov 16, 2020

Dustydazzler said:
quentic switches would have been the best option

Forgot about them, see new products old sweats like me forget.

Pretty Mouth · Nov 16, 2020

Dustydazzler said:
quentic switches would have been the best option

I think the OP had metal accessories in mind. Do quinetic do modules to fit? Would be a good workaround if so

Vortigern · Nov 16, 2020

I would recommend quinetic in that situation but the cost can be offputting.

Vortigern · Nov 16, 2020

westward10 said:
6181Y.

don't think you could have got all those down there though, same situation as a three core and earth with two core and earth.

westward10 · Nov 16, 2020

Vortigern said:
don't think you could have got all those down there though, same situation as a three core and earth with two core and earth.

They would fly down?

Master Mech · Nov 16, 2020

7029 dave said:
Okay understand that, 1.5mm cable was a bad choice, 1mm cable's might have gone down together with a bit of lubricate such as fairy liquid thats what I have used, failing that chase out the other switch drop, or surface mini trunking.

Apologies if I am getting the wrong end of the stick but when you say 1.5mm cable was a bad choice you are saying that 1.5mm2 cable was used?

I can 100% confirm that all the cables used were 1.0mm2 both the three core & the twin & earth.

What seems to have happened back in the 50's when the conduit was installed they had the fantastic idea to flatten/crush the conduit a little that was plastered into the wall so it is more oval than round.

I can only guess but it seems they did this to avoid having to chase the walls out as much.

Even when using 1.0mm2 cable there was no way a three core with twin & earth way going to fit down that conduit with the sheath. He did try with fairy liquid as he asked me for my help to try & pull them through with him.

Intoelectrics · Nov 16, 2020

Personally I would have done things differently, my main concern would be at the entry to the split metal conduit. But I'm not going to jump on the electrician who did this work when we only have one side of the story.
No offense to the OP but we are not privy to what you agreed, cost, limitations, timeframes... It only appears to me that the electrician was trying to save you the headache of redecorating. Maybe there were alternative solutions to overcome this, difficult to say without actually surveying the job ourselves.

To the OP,
have you invited the electrician back to comment/fix any of the things you have pointed out to us?

Intoelectrics · Nov 16, 2020

Master Mech said:
Even when using 1.0mm2 cable there was no way a three core with twin & earth way going to fit down that conduit with the sheath. He did try with fairy liquid as he asked me for my help to try & pull them through with him.

So at this point did the electrician not suggest an alternative? Since you were witness to the fact that the cables could not be pulled down the conduit, you knew that there was a problem?

Master Mech · Nov 16, 2020

Intoelectrics said:
Personally I would have done things differently, my main concern would be at the entry to the split metal conduit. But I'm not going to jump on the electrician who did this work when we only have one side of the story.
No offense to the OP but we are not privy to what you agreed, cost, limitations, timeframes... It only appears to me that the electrician was trying to save you the headache of redecorating. Maybe there were alternative solutions to overcome this, difficult to say without actually surveying the job ourselves.

To the OP,
have you invited the electrician back to comment/fix any of the things you have pointed out to us?

I have him coming back to change the 32 amp MCB on the radial he fitted for a 20 amp MCB.

Like I said in another post when I brought up the above issue he was not a happy chappy so I would imagine it will be the same for the issues discussed in this thread.

I will talk to him about the issues people have brought to my attention in this thread which was the whole point of me creating this thread.

I am an automotive tech & when I looked over the work I saw a few things I was not happy with but this is not my industry so I have not clue if this work was acceptable or not so thought I would ask here to get advice from the people that do before approaching him.