John P
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| posted on 25/4/09 at 07:51 PM |
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Earth Bonding in Bathroom
Hi,
I'm fitting a new toilet and wash basin into an existing cloak room and at present there isn't any obvious earth bonding.
If I fit a standard earth clamp to each pipe below the new basin and connect these together with 4mm cable is this all that needs to be done or must
it go to the earth connection of the ceiling light.
Simply connecting the pipes will be easy but running cable to the light almost impossible without doing major damage to the decotations / tiling.
Also, what should I do about the toilet?
Any help or an idiots guide would be much appreciated.
John.
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Thinking about it
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| posted on 25/4/09 at 08:14 PM |
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I think with the new regs it has to go to the consumer unit.
An electrician will be along soon.
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nitram38
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| posted on 25/4/09 at 08:30 PM |
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No, you do not need to run an earth to your consumer unit.
Equipotential bonding is between your pipes and any other metalwork such as a bath or if you have an electric shower, to it's earth.
Depending on the size of the room, there are different zones that require earthing, but for the layman, just do everything you can.
So link the pipes between taps and any metal drains etc at the bath and again at your washbasin.
Oh, and under BS7671, your bathroom lighting and any power items require 30mA rcd's now.
A simple washroom will be ok with just the taps.
[Edited on 25/4/2009 by nitram38]
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daniel mason
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| posted on 25/4/09 at 09:34 PM |
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if the circuit is protected by an rcd then it does not need supplementary earth bond anyway. no supplementary bonded is needed with 17th edition regs
as long as its 30ma protected,
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SteveWalker
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| posted on 25/4/09 at 10:18 PM |
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And of course if you use plastic piping, so no metal pipework is accessible and your taps, etc. are isolated from earth, you won't need to worry
about bonding anyway.
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nitram38
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| posted on 25/4/09 at 10:23 PM |
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Not sure about the rcd no bonding comments. Can you point to the section in BS7671?
Voltages on pipework can appear regardless of rcd protection because of different resistance in the pipe runs.
The pipes might also become live because of external influences outside the zone of protection.
My advice is to still bond pipework in bathrooms irrespective of an rcd.
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v8kid
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| posted on 26/4/09 at 09:30 AM |
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RCD on the lighting circuit? I always thought that was frowned on as spurious tripping could cause slip, trip & fall hazards if it was dark.
Is there a companion regulation requiring battery back up lighting?
Cheers
David
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nitram38
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| posted on 26/4/09 at 09:40 AM |
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quote:
Originally posted by v8kid
RCD on the lighting circuit? I always thought that was frowned on as spurious tripping could cause slip, trip & fall hazards if it was dark.
Is there a companion regulation requiring battery back up lighting?
Cheers
David
All circuits above 50V now have to have rcd protection in a bathroom. The way around this is fit extra low voltage lighting. (e.g. 12v halogens)
Additionally if any of your wiring is not installed deeper than 50mm from the surface or protected by an earthed metal cap/conduit, then it must be
30mA rcd protected.
Most homes only have twin and earth about 20mm from the surface so now the entire house should be rcd protected.
I don't make the rules, so don't shoot me!
P.S. I have just passed my 2391 testing & inspection exam!
[Edited on 26/4/2009 by nitram38]
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SteveWalker
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| posted on 26/4/09 at 10:24 AM |
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The reason for not putting lighing on the RCD was always that if there is a problem it would usually be with an appliance, not the lighting and
whatever was going on, you wouldn't want to be plunged into darkness as well.
New installations are expected to have at least two RCDs, with the downstairs sockets and upstairs lighting on one and the upstairs sockets and
downstairs lighting on the other. If there is an incident with an appliance, is shouldn't affect the lighting in that area.
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JoelP
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| posted on 26/4/09 at 09:02 PM |
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quote:
Originally posted by nitram38
Not sure about the rcd no bonding comments. Can you point to the section in BS7671?
Cant quote a reg number but thats how i understand it now. Hopefully Daniel will have details!
Multiple RCBOs ftw.
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v8kid
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| posted on 27/4/09 at 09:34 AM |
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Congrats on passing exam Nitram it used to be tough and sounds tougher now. The two rcd principle sounds v.good I may upgrade my consumer unit one wet
Sunday when I'm bored!!
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