Rcd Needed For An Outside Light?

[Benny_Boy]

Evening fellas,

I'm doing an outside light for my neighbour as a minor for my NICEIC assessment.
The house is on a fairly ancient consumer unit with what look like square-d breakers. Haven't had the cover off yet, just a brief glance so not sure if bonding is present let alone effective. Obviously not an RCD in sight.

Only 4 circuits, sockets, lights, immersion, kitchen socket. The last chap had even left info+diagrams in the CU!

If I stick a switched fused spur on the sockets upstairs will it need to have an rcd to protect any subsequent wiring for the light? I'm planning on chopping in next to an existing socket (still mounted in skirting board) and going straight out the backbox with some carbon black 1.5mm flex, out the wall and straight into the light with probably 50mm flex exposed before it terminates.

My understanding is that as it's not a socket outlet it won't need an RCD to comply. The additional wiring (just to extend the ring through the spur) won't be at a depth greater than 50mm but I've just read some blurb from Elecsa which seemed to suggest that the cable up to the spur would not need to be RCD protected, and if that doesn't need and RCD then I can't see how the cable for the PIR security light would need one.

I realise we're only talking about the cost of an RCD FCU as opposed to a regular FCU but I would like to have it clear in my own mind.

Sorry for the essay,

Any thoughts chaps?

many thanks
Ben

 

[Jason Smith]

Any thing outside of the equipotential zone of the house needs RCD protection, however, as its a light on the house wall, we need to know can anybody touch this light and be in contact with the general mass of earth , how high up the wall is it ? This is a good question of yours and may get a few replies- I am getting the books out !!

 

[Benny_Boy]

Any thing outside of the equipotential zone of the house needs RCD protection, however, as its a light on the house wall, we need to know can anybody touch this light and be in contact with the general mass of earth , how high up the wall is it ? This is a good question of yours and may get a few replies- I am getting the books out !!

It's out of reach and approx 4m up the wall. Pole vaulters might have a good stab but apart from that it's only going to be birds.

 

[Deleted member 9648]

Any thing outside of the equipotential zone of the house needs RCD protection,

Fixed equipment not part of a TT system doesnt.

 

[Benny_Boy]

Fixed equipment not part of a TT system doesnt.

Can you point me to a reg please?
I've poured ove rthe BRB for ages looking for something like that!

cheers
Ben

 

[Jason Smith]

what we got then beny boy ?- TT ? TNCS etc, etc ?

 

[Benny_Boy]

tn-c-s mate

 

[Deleted member 9648]

Benny boy, 411.3.3.....page 47

 

[Benny_Boy]

411.3.3.....page 47

off to the van now to get BRB!
back in 2

 

[Benny_Boy]

411.3.3 only seems to talk about allowing exceptions for socket outlets for skilled people or specifically labelled equipment.

or am I being a berk. (has happened before)

 

[Jason Smith]

sorted then bud, no rcd required as its fixed and not part of a TT system. Reading the reg now as well. Quick tip, you say 50 mil of wire to the fitting, dont forget to loop up to the fitting so the rain water runs off the bottom of the loop and not into your fitting- those glands suplied with the fittings are no good. might just stop an earwig. Sorry if suck eggs etc.

 

[Benny_Boy]

sorted then bud, no rcd required as its fixed and not part of a TT system. Reading the reg now as well. Quick tip, you say 50 mil of wire to the fitting, dont forget to loop up to the fitting so the rain water runs off the bottom of the loop and not into your fitting- those glands suplied with the fittings are no good. might just stop an earwig. Sorry if suck eggs etc.

I'm probably being a bit dim here but I still can't see exactly where to find something which applies to my scenario here.

The nearest thing I can see is 411.3.2.3 but that's for a distribution circuit not a final. Which bit are you looking at Jason?

cheers

 

[Jason Smith]

me too, further research is underway.

 

[Benny_Boy]

I'm beginning to think that this is an issue which might come down to the preference of your competent person scheme provider. I would be happy to be corrected.

It just seems silly to RCD a total of 40mm of inaccesible flex.

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Heston Blumental is making me hungry!.....back in a bit when I've filled me pie hole!

 

[Jason Smith]

well i accepted what wire puller said, bearing in mind you may need an answer by tomorrow, then went to the reg, which as you say doesnt seem to apply, so am doing further research. At the moment gonna stick by myoriginal post but non commital til I get an answer from somewhere.

 

[Benny_Boy]

well i accepted what wire puller said, bearing in mind you may need an answer by tomorrow, then went to the reg, which as you say doesnt seem to apply, so am doing further research. At the moment gonna stick by myoriginal post but non commital til I get an answer from somewhere.

answers by thursday on a postcard please!

seriously though, thanks for taking the time to look at this. It's a bit of a puzzler.
I'd just like to have something definitive, so I can guarantee that what I'm doing complies.

Kids will no doubt be up in about 4 hours so I'm going to catch 40.

Thanks again
Ben

 

[Deleted member 9648]

Sorry guys,should have been more specific
Reg 411.3.3 states where additional protection by means of RCD is required....(ii) states mobile equipment not exceeding 32a for use outdoors. There is no mention of RCD protection to fixed equipment for use out doors.
I added in the TT bit as obviously in a TT system all circuits are going to be RCD protected.
Not sure where you are getting the requirement to rcd all equipment outdoors from .....is there a reg or something else I've missed?

Fixed equipment in normal,non special locations, outside, is not mentioned specifically in the regs as far as I can see. If there were any special requirements for additinal protection it would be there,whats not in there is just as significant as whats in there.

EDIT....re the competant person scheme 'preference'....as far as I'm concerned they can only justify a preference if they can back it up with a reg!!

 

[Benny_Boy]

I've just found the following in chapter 5.7 (Outdoor lighting and power, sheds and garages) in the electrician's guide to the building regs (little green book)

"5.7.4 Fixed Equipment

Fixed equipment in the garden such as permanent lighting attached to buildings, should be securely erected with all cables buried or securely fixed to permanent structures clear of the ground. All insulated class II equipment is recommended where possible. Outdoor fixed equipment is not required to be protected by an RCD. A disconnection time of 0.4 seconds is required."

I think that wraps that up.

 

[Johno]

if i were you, i would explain that a new cu was necessary, and don't waste your time on cuting corners. though obviously a new cu can open a can of worms, but hopefully all ok.

 

[Jason Smith]

if i were you, i would explain that a new cu was necessary, and don't waste your time on cuting corners. though obviously a new cu can open a can of worms, but hopefully all ok.

Sorry Johno, gonna take you to task on this one. I agree that a new CU is the ideal scenario, but there is no evidence of cutting corners here, which as I am not as sensitive as others,may however be seen as a tad derogatory. The electrician just needs to add a simple lighting point and has received good advice on how to. I have learnt from this post, and the customer has also benefited from the knowledge and experience on this forum in that they are not left with a sudden estimate for hundreds of pounds when all they wanted is an outside light. My opinion, sibmitted with respect.