Questionable advice from an electrician.

[xtreme090]

I recently had an electrician visit to quote on replacing my main circuit board with split load RCD type.

I've been doing some rewiring and asked if he'd sign that off too, which he said was fine since it would be covered by the testing of the installation during the fitment of the new board.

When he saw the work I had done on rewiring the lights upstairs and fitting a new bathroom he said I would have to make sure that not only the bonding in the bathroom was up to scratch, but also that I should put an earth strap between the plumbing and the earth of the lighting circuit.

I can do this, but I've never read it before, and if the earth in the lighting circuit is the standard one you get in a 1.5mm twin/earth cable, what size of cable do I use to strap to the plumbing, which is all earthed with 6mm.

Any advice would be appreciated.

Cheers

Doug

 

[RF Lighting]

Yep he is quite correct.

You should contiue the bonding to all electrical services which enter the bathroom in the same size cable as the rest of the equipotential bonding.


//www.diynot.com/wiki/electric...l_bonding:supplementary_equipotential_bonding

 

[Lectrician]

Makes a change to see a spark go in to change a consumer unit and actually know what he is talking about!

4mm would have sufficed for the bonding, but many councils spec 6mm as their minimum for their jobs. You need to take this bonding from the pipework you have already done to any circuits within the bathroom - lighting, shower, towel rail, fan heater etc. If you have more than one light and a light switch (all the same circuit), you need only bond one (assuming they are connected together with a cpc).

 

[securespark]

many councils spec 6mm as their minimum for their jobs.

Are they becoming arrogant and making up their own rules, like the NIC?

 

[Lectrician]

It has always been like that when we do work in council owned care homes and council houses.

 

[streetlighter]

I always use 6mm for supplementary bonding as i can get it for nowt from work

 

[ban-all-sheds]

Can you get some for me?

 

[Lectrician]

You may need to run it back and forth a little bas.

 

[TicklyT]

......many councils spec 6mm as their minimum for their jobs......

I found both 6mm where you would expect 4mm supplimentary bonding, (and a few places you wouldn't, including each of the five legs of a fibreglass bath and the plughole of the ceramic basin connected to plastic waste pipe) AND a 10mm bond back to the MET after the council had been at work.

I don't think they had really grasped the concept of supplimentary bonding.

In the circumstances, the additional 10mm would probably make little difference, as it clamped to the cold water pipe about 6 feet directly above a 16mm earth at the stopcock in the kitchen directly below.

What is the CSA of 15mm copper pipe? somewhere about 25 - 35 mm?

 

[ricicle]

What is the CSA of 15mm copper pipe? somewhere about 25 - 35 mm?

Around about 44mm² if you assume that the wall of the pipe is 1mm thick.