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#139389 - 11/02/03 03:27 PM RCD protection on lighting / lighting sockets?
djk Offline
Member
Registered: 12/26/02
Posts: 1237
Loc: Ireland
Ireland has required RCD protection on all sockets and fixed appliences and water heaters since 1980 but lighting along with cookers were exempt. (Electric showers require seperate RCD/RCDO protection) I never understood why light fixtures were not included as they're one of the most likely places to get a shock either during DIY work or when changing a bulb.

If you're fitting 5A light sockets to a non-RCD system they fall under the normal regulations for socket outlets and require RCD protecton. The only options are to either rewire the whole distribution panel (Consumer unit) so that the RCD covers the lights which can be a huge undertaking for the sake of 2 lamps or alternatively install RCD protection locally e.g. using RCD spurs. i.e. a spur plate that contains a 5A fuse and an RCD connected in before any switching/dimming complicates the wiring.

Light fixtures are now required to be covered by the system-wide RCD What's the situation elsewhere?

Do you consider it necessary for lamp outlets? or are we being completely over the top?

There are proposals to require a lot more RCD protection in future revisions of the wiring regulations.
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#139390 - 11/02/03 03:51 PM Re: RCD protection on lighting / lighting sockets?
Hutch Offline
Member
Registered: 05/27/02
Posts: 381
Loc: South Oxfordshire, UK
South Africa, which pioneered RCD protection, has gone to and fro on its application over the years and it depends on which province one lives(d) in. At one time, Natal had everything on RCD, then it removed the requirement for immersion heaters and then removed the requirement for lights. At one intermediate stage they wanted separate RCD for the immersion and general circuits which was too pricy to endure. The idea of taking the lights off RCD was that if a leakage occurred on a power circuit, the lights wouldn’t all go out and create more danger. In general…

RCD Protected:
All power (socket & plug) circuits – 20A radials
All outbuildings – Sub-panel 25A feed or light+1 socket (20A – all 2.5sq.mm)
No RCD
All house lighting – 10A radials (5A BS546 lighting sockets included)
Cooker,
Immersion heater
Fixed appliances

I assume from this that the main threat to safety was perceived to be through faulty/misused plugged-in appliances.
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#139391 - 11/03/03 04:41 AM Re: RCD protection on lighting / lighting sockets?
C-H Offline
Member
Registered: 09/17/02
Posts: 1497
Loc: Stockholm, Sweden
I remeber reading a Swedish article about this a few years ago. The writer argued that a house-wide 30 mA RCD is a good solution for an ordinary home. There are possible problems with this, but these problems rarely occur in reality.
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#139392 - 11/03/03 04:54 PM Re: RCD protection on lighting / lighting sockets?
David UK Offline
Member
Registered: 10/03/02
Posts: 134
Loc: Inverness, Scotland
I think RCD protection for lighting circuits is a good idea, providing it is a seperate RCD or RCBO for the lighting circuit(s) only.

RCD's are getting cheaper all the time, I can buy a 40A 30mA RCD for only £18+VAT (€25)at the moment, used to be closer to £30.

Some local authority houses here have consumer units fitted with 2 30mA RCD main switches. A 40A RCD with 2 or 3 ways for lighting circuits, & an 80A RCD with 6 to 8 ways for power circuits, including cooker.
This is not an ideal solution but it does mean the lights stay on if an appliance is faulty, & the power is on if there is a fault on the lighting.

There is currently no specific requirement to RCD protect lighting circuits in the UK, unless the earth loop impedance values are too high (TT earthing) or the light is fitted in the resticted zone 1 of the bathroom.
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#139393 - 11/03/03 05:40 PM Re: RCD protection on lighting / lighting sockets?
djk Offline
Member
Registered: 12/26/02
Posts: 1237
Loc: Ireland
It looks like we're going to be installing a LOT of RCBOs in Ireland in the not too distant future.

TT systems have poco sealed RCD system here.
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#139394 - 11/04/03 03:27 AM Re: RCD protection on lighting / lighting sockets?
pauluk Offline
Member
Registered: 08/11/01
Posts: 7520
Loc: Norfolk, England
Personally I don't consider RCD protection necessary for all circuits, but if we're going to go that route, then I'd like to see individual breakers, or at least split-bus units so that a ground fault doesn't take out power to the entire house.

As for TT in general, I don't think it's any big secret that I'd like to see this arrangement done away with as soon as possible.
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#139395 - 11/15/03 08:42 PM Re: RCD protection on lighting / lighting sockets?
Trumpy Offline


Member
Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
Paul,
I'd agree there.
Under the latest round of Standards here, we are now required to install RCD's on all new circuits (excepting Ranges and Refrigeration equipment).
The thing that I don't like about this, is the fact that the lighting circuits, generally, are the first circuits to cause a fault in an installation.
And like you said yourself, the need for individual RCD's becomes necessary, to avoid plunging the whole house into darkness.
It's things like this happening that cause safety devices like this to be bypassed, sometimes poorly, which defeats the point of even having them in the first place.
In any installation I've ever done using RCD's, I usually stipulate to the owner that they have a minimum of 4 RCBO's installed (2 of these on the lighting circuits).
And although I shouldn't really, I've installed a non-protected light next to the switch-board on more than one occasion.
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Let's face it, these days if you're not young, you're old - Red Green grin
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#139396 - 11/16/03 12:39 PM Re: RCD protection on lighting / lighting sockets?
djk Offline
Member
Registered: 12/26/02
Posts: 1237
Loc: Ireland
Well given that there are generally only a few lighting circuits (compared to socket/power circuits) it can't really push the cost up by that much to install a few extra RCDs. If you have 2 you can alternate lighting zones up and downstairs between them.

I actually think it's quite important to have RCD protection on lights though as they're one of the most likely places to get a minor shock.
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#139397 - 11/16/03 08:23 PM Re: RCD protection on lighting / lighting sockets?
Trumpy Offline


Member
Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
Oh and by the way,
What I mean't by un-protected, above, was without RCD protection.
The day when I start hooking things up without fusing, is the day when I commit myself!.
Just wanted to clarify that.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin
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#139398 - 11/17/03 02:05 AM Re: RCD protection on lighting / lighting sockets?
pauluk Offline
Member
Registered: 08/11/01
Posts: 7520
Loc: Norfolk, England
Fuses for lighting? Spoilsport!

How much does, say, a 16A RCBO run in New Zealand?

One of the problems of trying to use individual RCBOs here is the cost of the things, typically £30 as opposed to £5 for a regular MCB,
http://www.tlc-direct.co.uk/Products/CM91603.html
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