Builders' bad wiring

[mrmiles]

Hi,

Builder's putting in 5 plug sockets in an attic space (already converted but never used) - when I looked at what he's done, he's wired them up like lights! There's a junction box and then the 4 sockets come off that. One socket then has a further spur off it.

From what I've read, this is not right - does it definitely need changing (I only found it by chance, once the painting has started). If so, is it better as a ring or a radial, or can he choose the least destructive option?!

Thanks!

M

 

[ColJack]

it may already be a radial.. we don't know what the supply to it is..
while not the best looking, if it's a radial there's nothing technically wrong with wiring like that..

 

[rebuke]

It's not necessarily wrong - if it's a radial circuit, then there's nothing wrong with using a junction box (as long as the box is accessible), and equally nothing wrong with running sockets off sockets.

If however it's a ring circuit, then this is definitely wrong, and rather dangerous. Do you know if the circuit is RCD protected, and what rating breaker it's on etc (pics of consumer unit and the wiring might be useful)?

 

[flameport]

Almost certainly wrong.
Even if the circuit was a radial to start with, it's still a poor design.

What size of cable, and what size of fuse/MCB for the circuit?

 

[mrmiles]

Hi,

Thanks for the speedy replies!

It's wired in 2.5mm2 cable, the CU fuse is 32A. It's on the RCD side of the unit.

I'm not there at the moment, so can't post pics.

Basically (hope this makes sense), there's one 2.5mm cable into the junction box directly from the CU, then 3 2.5mm cables out, each ending in one double socket. One socket has a further socket connected off it, again by 2.5mm cable.

(The junction box is hanging in mid-air, but that is easily sorted. At least it is easily accessible)

M

 

[flameport]

It's wired in 2.5mm2 cable, the CU fuse is 32A.

Wrong and dangerous then.
Changing the 32A to a 20A would rectify the problem (provided the cables are no in insulation etc.), however it's still a poor design.

Is anything else connected to the same MCB in the consumer unit?

Far better to take the cable from the CU to the first socket, then the 2nd socket, 3rd and so on - no need for the junction box at all.

 

[ColJack]

it's a radial then, but shouldn't be on a 32A breaker if it is 2.5mm²..
make sure it is 2.5mm² and that there is only one cable in the breaker..

 

[RF Lighting]

So this is a new circuit then?

 

[mikhailfaradayski]

It's wired in 2.5mm2 cable, the CU fuse is 32A. It's on the RCD side of the unit.

No need for pictures, given your desciption, its wrong.

 

[sparkyspike]

Basically (hope this makes sense), there's one 2.5mm cable into the junction box directly from the CU, then 3 2.5mm cables out, each ending in one double socket. One socket has a further socket connected off it, again by 2.5mm cable.

This sounds like a radial. Are you sure that the first cable comes directly from the CU and hasn't been spurred off somewhere else?

One way to find out is to look at the breaker and see if it's a ring (you can do this with a multimeter).

Ask the person who installed it to explain what has been done.

 

[mrmiles]

Thanks all for your responses.

I traced the cable from where it enters the CU up to the junction box (this is easy from the floor below), there are definitely no spurs before the junction box. There's definitely nothing else connected to the MCB. It was a new circuit.

Changing the cable run to remove the junction box, as suggested by flameport, would mean hacking some plaster out of the walls to connect the plugs and then re-skimming and painting, which I'd like to avoid unless absolutely necessary just because I'm keen to see this work finish!

So, in conclusion, although it's not the best design, it's acceptable once the MCB is changed for a 20A one, and JB secured to the wall.

 

[Taylortwocities]

Yes, that would technically sort it.
Now, as it is a new circuit, the builder must notify it to the local authority. I assume he is registered to notify that his own electrical works comply with Building Regulations Part P?

Is he listed here?: www.competentperson.co.uk