Cable routing

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Lew
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Cable routing

Post by Lew » Thu Jun 07, 2018 9:07 am

We are planning to knock down our old porch & replace this with an extension about 4 times that size. The porch currently has 2 sockets on a ring main which includes another 2 sockets in the hallway. Similarly the light comes off a circuit shared with the hall light.

The new (external) walls will likely be something like brick-cavity-kingspan-breezeblock-plaster.

1) I was wondering what would be the best place to route the cables when we rewire part of that ring main? As we are building it, I could for instance run them (in a conduit?) through that cavity - or would that be consider 'outside'? It will only be 3 or 4 sockets.

Alternatively I could run them (like the lighting circuit) through the ceiling and trace them down through the breezeblock/plaster.

2) Am I correct in assuming that I am only altering an existing mains ring and an existing lighting circuit and therefor this is, in Wales, non-notifiable work?

Unfortunately, the current porch is where our electricity enters the house. It first has a 100A fuse (seal long gone) then the meter and then a service connector block with 2 leads, one going outside to a small fusebox in the outbuildings and one to the main consumer unit in the hallway.

3) How do I go about getting that redone? I would preferably move the meter to the hallway next to the consumer unit. Would I have to pay Western Power for this?

and lastly

4) I have so far not given in to having a smart meter .. can I still have a non smart meter if they are replacing it?

Lew
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ericmark
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Re: Cable routing

Post by ericmark » Fri Jun 08, 2018 7:44 am

The major problem is getting meter etc moved, this has to be done by the DNO and even for electricians it is a pain, I have sat in my car many times waiting for the DNO to arrive where they insist an electrician is present and seem to be unable to give times.

Most houses have freezers etc, so once moved you want power back on ASAP. Also you want single visit by DNO or your paying twice.

My son has moved the location of his consumer unit, he cleared it with the DNO that the power can be transferred to new location, and has temporary tails to old location, been like that for around three years waiting for DNO to complete their bit. OK he is not in a hurry, but this is normal for DNO.

As to Welsh Part P moving or replacing a consumer unit as with English would require notifying, in theory when you pay your £100 plus vat the building inspector should either inspect and test, or arrange for some one to inspect and test for him. In practice the one time I went down this route, he was not very willing to allow us to do the work, but once he realised we did have the skill required we never saw him again. I handed in the paperwork to the Shirehall, and a completion certificate arrived in the post, nothing was inspected or tested by the building inspector, OK because for the disabled there was no charge, but in real terms it would have been £100 plus vat for nothing.

As to cables outside, I have run SWA around the outside of building many times rather than try to find an internal route, there are a number of considerations.
1) Cooling, will the cable overheat if that route is followed?
2) UV resistance, will the sun affect the cable?
3) Physical damage, can something hit and damage the cable.
4) Volt drop and earth loop impedance, will the extra length cause problems?
It is really common sense, often we can see if there is likely to be a problem well before we start to measure, so often we do the job, then measure and fill in paperwork. However some times you look at a job, and realise it is going to be on the edge, so you measure first.
Lew
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Re: Cable routing

Post by Lew » Fri Jun 08, 2018 8:18 am

To be clear. The consumer unit doesn't need to be moved. This is in the hallway. It is just the 100A fuse & the meter which are in the porch (about 10 ft away from the consumer unit). The overhead cables attach to my house on the external wall of the hallway with the consumer unit in it. But rather than going in through that wall, they have routed a cable from where it attaches for probably 20 ft around the outside of the house and then into the porch where my meter currently is.

The more important question however was if I can run a ring main through a cavity wall or if this was considered bad practice (and if I do - do I need conduit).
OnlyMe
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Re: Cable routing

Post by OnlyMe » Fri Jun 08, 2018 5:40 pm

It would be better practice to route the cables through the ceiling and behind the plaster.
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