Bathroom cross bonding

[ChrisR]

1) If I read it right, I have to cross bond between eg the ceiling lights and the underfloor heating. Is that right, and does it really happen?
Suppose the lights are 12V but metal rimmed?

2) Am I allowed to do this as diy in my own home - do I have to inform LBC under Part P? I do not have IEE 16th compatible test equipment.

Thanks chaps.

 

[securespark]

Yes, but not only between the cpc's (earth conductors) of circuits feeding equipment in the bathroom, but extraneous conductive parts like baths, pipework, radiators etc...

Yes! It does really happen!

ELV lighting by design is not earthed, but if you bonded the cpc of the lighting then if the fittings were changed in the future, the circuit would be already bonded.

Bonding within the bathroom is notifiable, but whether you do that or not.......

 

[Spark123]

1) If I read it right, I have to cross bond between eg the ceiling lights and the underfloor heating. Is that right, and does it really happen?
Suppose the lights are 12V but metal rimmed?

You should cross bond between any extraneous metal parts and protective conductors of each circuit supplying class 1 & 2 equipment in zones 1,2,3 unless they are fed from a SELV source. A ceiling light may be outside these zones and therefore will, in these circumstances, not require cross bonding. 12V lights in any zone fed from a transformer to BS 3535/BS EN 60742 can be considered a SELV source and do not require cross bonding.

2) Am I allowed to do this as diy in my own home - do I have to inform LBC under Part P? I do not have IEE 16th compatible test equipment.

Thanks chaps.

Legally you should either contract out to someone who can self certify or you should notify LBC before carrying out the work.

 

[ChrisR]

Thanks.
I think, if I use plastic pipe, none of the bath, rad, rad copper tails etc need to be bonded (from the excellent sticky notes at the top, http://www.iee.org/Publish/WireRegs/EarthingPlasticPipes.pdf


But I thought I'd bung in underfloor heating, until I found
"Regulation 601-09-04 permits electric heating units
intended for heating the location to be embedded in the
floor below any zone, provided they are covered by an
earthed metallic grid or have an earthed metallic sheath
connected to the local supplementary equipotential
bonding."

Any suggestions where one would acquire a suitable metallic grid, or sheathed heating cable? I bet they've not even heard of them in Wickes.

 

[securespark]

The system I used (Warmup) had earthed heating cables. Don't f*nny around with a grid!!