Part P

[Bas]

I'm currently preparing for an inspection as part of my Part P registration and have a question. The installation I'm working on as part of a bathroom refurb does not have its main water supply pipe bonded to the main earth terminal. The gas is.
The bathroom will have a heated floor and new shaver/light. Luckily there is an existing unused radial circuit from the fuseboard (used to be for a shower) so my electrical work is easy.
On my 2381 course the instructor advised us to note such departures on the minor works form but I'm concerned the NIC inspector will defer the inspection because the bonding connection is absent. Any views would be appreciated.

 

[dingbat]

You might find it useful to read this: http://www.niceic.org.uk/nonapproved/departures.html

 

[Damocles]

So back to the thorny question of whether it is necessary to rewire the whole house when what has been requested is an additional socket.

 

[revolt3k]

so how did you go on bas did he say anything about it?

Whats the inspection like from the NICEIC ?

cheers

 

[Big_Spark]

So lets get this picture straight from the off.

You are undertaking a Bathroom refurb, and in this bathroom is a Gas Boiler.

This boiler has a Main bond from the Earth Terminal of the Supply attached to it.

1: Is this Gas feed the main in the building..simple answer is no, therefore it does not require a Main bond. However the Main bond should go to the point where the gas supply enters the building, but on the consumers wide of the meter..as we all know already.

2: The Boiler must have a spur feeding it, therefore a 6mm bond from the Earth terminal of the spur to the Gas pipe with necessary cross-bonding will be sufficient and comply with the regulations.

3: The Water pipe feeding the bathroom does not need a main bond that goes back to the main Earthing terminals. It does, however, require a bond from the nearest Earth Terminal, as with the boiler. Then all the water pipes require cross-bonding.

Now it may be practical to simply cross-bond all the pipework using the Earth Terminal in the boiler spur as your Earth Terminal as the source, without seeing the installation I cannot say.

There is a school of thought that it is actually unsafe to take a bond back to the Main Earthing Terminal from a bathroom..I cannot follow the so called logic on this arguement as the bathroom is bonded anyway and their arguements are contradictory, but I have heard of NICEIC inspectors considering the feeding of a bond to a bathroom as a deviation from the regs..

 

[mapj1]

The school of thought goes like this.
Imagine we have a defective shower/heater/light whatever that is not on an RCD, in the bathroom. If the fault current returns via the circuit earthing instead of neutral, then the metal case of that object, at least until the fuse blows, is at a higher potential than the MET. If you have wet hands, and this exceeds 25V if you are really unlucky, it could be lethal, if you were also touching somthing that WAS at MET potential.
It is safer, then, if the bathroom is a long way from the MET, to bond all the circuit earths and the bathroom hardware together at the bathroom end. Then, even during the fault, it is all still at the same voltage, even if that is a little high, and you cannot receive a dangerous shock, if you are touching two metal things at once.
That said, such faults are rare enough that it is very doubtful if bathroom bonding saves any lives at all most years. Compulsory RCDs for all electrics in the bathroom would probaby be more sense.

regards M.

 

[Bas]

No, the boiler is elsewhere. I have refurbed the bathroom and when it comes to testing the electrical installation I note there is no main bonding to the incoming water main. Therefore it will fail an inspection but nothing to do with my work!
What would an inspector say if he were to come along to check my (minor) works.
I have yet to request the inspections as each installation has similar issues with it, all outside my control. I have passed the 2381, learnt to inspect and test!

 

[ban-all-sheds]

As long as your supplementary equipotential bonding is up to scratch, and you note the departure concerning the main equipotential bonding then I don't see why you should be in any bother whatsoever.