putting a lighting circuit on a RCBO

[tombrooker84]

Hello Guys,

I've got a garden lighting job to do, there is an exisiting supply, fed from a flexible conduit (not great, but without ripping up a patio it will have to do). Currently it is fed from from a MK sentry 16th edition split board, without RCD protection, so I was going to upgrade the circuit by replacing the MCB with an RCBO, however this obviously means I take responsiblity for the entire circuit, and there are literally 20 X MR16 12V fitting on the circuit, all fed from dimmer switches and the house is beautifully decorated. How would you go about testing them? I mean doing an IR test will be nigh impossible unless at 250v? And R1 + R2 just at the switches and not the fittings?

Cheers

Tom

 

[telectrix]

can't you take the outside feed off that mcb and fit a separate rcbo? if you need to IR test the existing circuit, short out L/N at CU, then IR test to E.

 

[Octopus]

RCD FCU off the socket circuit?

 

[Farmelectrics]

^^^ as above

 

[Octopus]

Thing to remember about outdoor "anything" if its on an RCD shared with the house and without DP isolation any issues outside will affect the house and without DP isolation the client won't be very happy.

 

[gonefishing]

Why are you contemplating doing the garden work if the existing supply is (not great) you take responsibility and it's your arse in court and NICEIC won't back you up for not following regs, will they

 

[SirKit Breaker]

Why are you contemplating doing the garden work if the existing supply is (not great) you take responsibility and it's your arse in court and NICEIC won't back you up for not following regs, will they

I have to beg to differ on this one. I agree with what you are saying and it is good advice.
But he has obviously got enough knowledge to understand what he is doing, its not ideal but will have to do, he intends to make it compliant from a protection perspective, and this should be OK if the cable gives out, he is also no doubt going to certify/notify as appropriate, and he can cover his backside by clever wording on the paperwork.

In my opinion, he is making the installation safer than it currently is. I would rather someone competent did this sort of work, than the pub cowboy. If he doesnt do it, then someone else will, and it will be a bodgit and scarper merchant.

 

[tombrooker84]

Ideally I would of liked to put an RCD fused spur in, but unfortunately the supply is already into the garden with the switches already buried in the wall, just a neutral, switched live and earth through the conduit, and being that the supply to it is not ideal i thought it best to put an RCBO on it and protect that as well, rather than from that point on. I understand what your saying "gone fishing", but bar the patio the garden is getting landscaped and the house has just been decorated, and they do not want wires on show and the walls chased out, and the place has recently been decorated, and they have a baby on the way so want minimal disruption to the home. So I will note it on the certificate and explain that it is not ideal e.t.c.. I will obviously have to test the circuit and didn't want to be pulling down downlights e.t.c. It is a £2.5m house and the decor has cost them a small fortune from designers e.t.c. so a little nervous about leaving dirty fingerprints on ceilings and cracked paint from removing switches, but hey ho

 

[Deleted member 26818]

I can't see any mention of socket-outlets in the OP.
As far as I'm aware, there is no requirement for RCD protection.

Another thing, why do you believe that by replacing the MCB with an RCBO, you will be taking responsibility for the whole circuit?
You are responsible for what you install, nothing else.

 

[Paul.M]

"I've got a garden lighting job to do, there is an exisiting supply, fed from a flexible conduit"....


Cant you tap in at that point outside and use a 1 or 2 way IP65 shower c/u and save yourself the headache?

 

[tombrooker84]

As the supply in flexible conduit isn't ideal, I wanted to protect it, hence the RCBO at the board.

 

[telectrix]

it may not be ideal, but, as has been said, does it really need RCD protection?

 

[lauriehurman]

522.6.102
cables concealed in a wall.

assuming the object is to upgrade.

Laurie

 

[Octopus]

522.6.102
cables concealed in a wall.

assuming the object is to upgrade.

Laurie

IMHO not applicable if the cable goes directly through the wall.

 

[telectrix]

as murdoch says, if cable is not buried < 50mm no need for RCD protection.

 

[tombrooker84]

Cheers for the replies guys. I think although I may be able to get away with no rcd protection, for the £17 quid and an hour or so of testing, I'll think I'll just do it anyway. I'd rather be safe than sorry type of thing. Tom