Help,main water after a stop cock plastic

[arturas]

Hi there, i have been trying to find an answer everywhere but i couldn't.. so that's my problem, there is a stop cock which is about 300mm from a floor level, and after stop cock is plastic pipe connected which goes straight to boiler. Now the gas is coper and has been earthed within 600mm after stopcock and goes to boiler as well. Now is it enough to do a cross bonding under the boiler on all boiler incoming and outgoing coper pipes?or should i get new 10mm earth cable to boiler and then do cross bonding?should i bond the metal part of the incoming water before stop cock?thank you.

 

[Deleted member 9648]

which raise a point. suppose that the installation had wet underfloor heating, piped in copper. could this, being buried in a concrete floor, introduce an earth potential to the radiators?

Possibly yes.

 

[arturas]

In the bathrooms there will be one rad in each bathroom,from boiler to rads pipes are plastic,just before entering the rad there is a little bit of coper,theres no underfloor heating,but rads should be combined with heath element which i will connect to my flex outlets so that should give earth for them?or i'm wrong? And there is some rada in bedrooms,which ones alsow has just a little bit of coper before entering into the rads,should i be worrie about them?

 

[silentboarder69]

Presuming your using a dual RCD board, 17th edition only requires gas and water mains to be bonded, sinks, rads etc require no bonding, so no need to worry.

 

[Deleted member 9648]

Presuming your using a dual RCD board, 17th edition only requires gas and water mains to be bonded, sinks, rads etc require no bonding, so no need to worry.

Not entirely correct.Incoming services might include oil lines and structural steel amongst others that will require main bonding.
There are three conditions that have to be fulfilled in order to omit supplementary bonding in special locations.
1. All final circuits within the location are 30ma rcd protected.
2. Disconnection times are met for all circuits within the location.
3. All extraneous conductive parts within the location are effectively connected to the main bonding...this can be measured and should not exceed 1667 ohms.(701.415.2). Most people seem to miss this one.
It is not the case that RCD protection alone means supplementary bonding is not required in a special location.

 

[arturas]

yep that's true, but will heat element give the earthing to rads? ''All extraneous conductive parts within the location are effectively connected to the main bonding'' but then if everything runs in plastic pipes, does that matters?or it's still extraneous conductive part and has to be effectively bonded?the bath and shower basin is plastic so no problems with that..and yes i will use dual rcd board for this house. basically it's the first time for me when after stop cock is plastic and everything else is plastic and i couldn't find anything in regs or on site guide what would help.. i would like to get alecsa guy to check me on this site..

 

[telectrix]

from what you describe, it seems that the radiators are not extraneous, as there is no possibility of them introducing a potential, as they are plumbed in plastic. set your mft for 500v IR test and measure from rads to MET. if over 22kOhms, forget them.

 

[saveloy]

Not entirely correct.Incoming services might include oil lines and structural steel amongst others that will require main bonding.
There are three conditions that have to be fulfilled in order to omit supplementary bonding in special locations.
1. All final circuits within the location are 30ma rcd protected.
2. Disconnection times are met for all circuits within the location.
3. All extraneous conductive parts within the location are effectively connected to the main bonding...this can be measured and should not exceed 1667 ohms.(701.415.2). Most people seem to miss this one.
It is not the case that RCD protection alone means supplementary bonding is not required in a special location.

Amazing how many times I hear " the bathroom's on an RCD so it doesn't need supplementary bonding" !

Found this PDF that explains supplementary bonding in bathrooms.

http://www.alexscullion.co.uk/bs7671-2008supplementarybonding.pdf

 

[Deleted member 9648]

Amazing how many times I hear " the bathroom's on an RCD so it doesn't need supplementary bonding" !

Found this PDF that explains supplementary bonding in bathrooms.

http://www.alexscullion.co.uk/bs7671-2008supplementarybonding.pdf

I'ts simply amazing how many electricians dont understand bonding....see post 20...earthing radiators.

 

[arturas]

Thanks for everybodys answers

 

[mark_]

After reading this thread (late again I know) I thought id test the copper pipework for an installation we are on now. The water is polly incomming and polly throught the house except where there is a small amount of copper at the stop tap.

The meter didn't even register the reading on ohms so we moved to Meg ohms where by the reading of 35.8M ohms was found at 250v. Although we had bonded it, we didnt actually need to.

 

[Deleted member 9648]

After reading this thread (late again I know) I thought id test the copper pipework for an installation we are on now. The water is polly incomming and polly throught the house except where there is a small amount of copper at the stop tap.

The meter didn't even register the reading on ohms so we moved to Meg ohms where by the reading of 35.8M ohms was found at 250v. Although we had bonded it, we didnt actually need to.

I always main bond water with a plastic incomer regardless....as long as there is copper immediately after the stopcock.

 

[arturas]

In this case it was all way around, it was copper incomer, but immediate after a stop cock was all plastic..