Hi - noticed none of the CH system is earth bonded - I'd like to do it at ther boiler - easier as all pipes obvoiusly enter there :-) question is - could I sinply strap them all together with earth clamps and run a cable out to an earth rod? as the CU is the other end of the house and probably a 15m run with mucho hassle and mess :-( My head says it should be OK as earth is earth and should be at the same potential? but like to check first thanks :-)
earth bonding on CH system -
Feb 21, 2011
14 Replies
Think what would happen if your supplier-earth failed, particularly if it is TN-C-S and rose in potential to mains voltage (can happen, though unlikely, if the neutral wire breaks outside your property).
You'd then have some exposed metalwork at mains potential, and other exposed metalwork at your local earth-rod potential.
You must bond to the supplier earth.
See:
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yes its earthed in the plug to the supply - but none of the pipework is bonded in any way
I take it I'll need to run 10mm copper from the boiler to the CU ? also when bonding the pipes I just scrape back the insulation and clamp without breaking the 10mm ? As all pipes enter and distribute from the boiler will this be sufficient to preotect the rest of the house ? or will I need to earth the bathroom seperately as well? thanks, just thought I'd get it done.
If your incoming services (gas and water) are main bonded then it is doubtful that the CH needs to be main bonded. However some boiler manufacturers installation manuals require the boiler pipework to be supplementary bonded. All you need to do this is some 4mm earth cable (or larger if you want) and some earth clamps to bond all the pipes together next to the boiler. There is no requirement to take this cable back to the CU and many reasons not to take it to an earth rod. The cable used for supplementary bonding may be cut and joined at the clamps.
thanks :-) makes life easier
Staffbull ( snipped-for-privacy@googlemail.com) wibbled on Monday 21 February 2011
21:03:
Do what Adam says - he is a qualified electrician in case you didn't know ;->
Actually from the IET not me.
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most CH systems are not extraneous-conductive parts.
Owain
Treat yourself to a date with her, I am no longer married to her.
There is a photo of her 8 years later if you look through the files. I prefered her when she was 18 years old.
ARWadsworth ( snipped-for-privacy@blueyonder.co.uk) wibbled on Monday 21 February
2011 22:47:
You married a snow-woman?
Nah, that's her sister.
Owain
Bit on the cold side, was she?
(Or should that be cold bit on the side?)
Owain
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