Rewire by a competent person.

[ahuman1]

Hi all, (hello BAS)

I started a thread a while back about moving my meter, and got banned..

Hmm, DIY? or DIYnot? I'm wondering? I'm just doing my own place up to sell on, and move onto the next..

Anyway, I've found a great spark who is willing to let me do the 1st fix on a complete house rewire. In all honesty, the place doesn't need a full rewire, but the amount of work involved in extending circuits, new DB, etc, He said go for a full rewire including smoke detectors etc and he would do the 2nd fix and test, sign off the work. Making the place more sell able.

He has planned the downstairs lighting circuit, which involves 7 cables going into a single gang three way lighting switch.

I have plenty of room between the switch and ceiling. I have got 20mm oval tubing to run the rest of the wiring, but what am I supposed to do with 3 X 1.5mm 3 core and earth link cables and 4 X1.5mm t&e lighting cables (includes feed). Its loop in, and will also have to connect up 7 neutrals, all in a single gang back box? I've bought a 47mm deep one, but its gonna be a squeeze isn’t it??? also, how would one make the cables accessible, as they wont all fit in 20mm tubing.?

cheers.

 

[sparkwright]

Well, presumably it's not your problem where it comes to connecting up the 3 gang switch - because you're not doing the second fix.

Electricians nowadays regularly have that sort of high quantity of cables at a switch.

As you indicate, it would be sensible to fit a 47 mm deep box.

I suspect you won't have seven neutral wires to go in a connector block, because some of the cables will just be 3 core and earth 2 way cables - no neutral.

Either way, your electrician will be able to fit seven conductors to a connector block.

Not sure what the issue is with the 20 mm conduit.

Possibly you may need two conduit drops down to the switch - larger 25 mm oval conduit may be sensible here.

Careful planning should allow all the cables to pass through just two conduits - you only want two conduits as the top of the box will only have two knockouts.

Some 47 mm boxes have at least one 25 mm knockout in them, so this kind may be useful.

Don't forget, perhaps some of the cables can go from the switch DOWNWARDS then under the floor, if that would make life easier.

 

[sparkwright]

1.5 mm2 cables for the lighting?

This will take up valuable space in both the conduits and the switch boxes.

Usually there's no reason why one can't use 1.0 mm2 cable for domestic lighting.

May be worth asking your electrician if he's happy for you to use 1.0 mm2 for the lighting.

There's often no advantage using 1.5 mm2, but ask him before you make any sudden decisions.

 

[OwainDIYer]

use a double back box and a 4-gang switch, with one switch unused. Gives him a a lot more room to work in, easier than working in a single box, and easier to chop out a wide shallow box than a single deep box.

 

[sparkwright]

use a double back box and a 4-gang switch, with one switch unused. Gives him a a lot more room to work in, easier than working in a single box, and easier to chop out a wide shallow box than a single deep box.

NOOOOOOOOOOOOOOOOOOOO.

I hate switches that don't do anything.

He'll be fine with a deep single box.

That said, you could get a 3 gang switch to fit a double box - 3 gang grid system or a three gang dimmer.

 

[ban-all-sheds]

what am I supposed to do with 3 X 1.5mm 3 core and earth link cables and 4 X1.5mm t&e lighting cables (includes feed).

Take them to the switch position(s), identify them, and leave them long enough for the electrician to have enough to dress as he wants.

Its loop in, and will also have to connect up 7 neutrals, all in a single gang back box?

But that's his job - he'll be doing second fix, remember.

I've bought a 47mm deep one, but its gonna be a squeeze isn’t it???

He must have specified what size to use, as that has a direct bearing on compliance with the Wiring Regulations, which makes it a design decision relevant to his declaration on the EIC to say that he designed it and it complies.

also, how would one make the cables accessible, as they wont all fit in 20mm tubing.?

He must have specified how many and what size to use, as that has a direct bearing on compliance with the Wiring Regulations (Cg for example) which makes it a design decision relevant to his declaration on the EIC to say that he designed it and it complies.

Where did you find this guy?

Is he actually qualified?

How much are you paying him?

The signs are not good that he actually knows what he is doing.

 

[bernardgreen]

I hate switches that don't do anything..

They are a sign that the electrics may have problems. Not good when selling a house.
Who designed ( cobbled ) the installation ?

 

[sparkwright]

I hate switches that don't do anything..

They are a sign that the electrics may have problems. Not good when selling a house.
Who designed ( cobbled ) the installation ?

That was just an idea by another forum user.

I don't think the electrician on this job is necessarily a bad one, he's just left a few unanswered questions, that's all.

The op can easily ask his electrician if there's any doubt.

No reason why a switch shouldn't have some many cables - that said, sometimes things can be re-designed to get fewer cables at one switch, and slightly more at another.