bonding to chrome water pipe

[colorado]

I've discovered I have no bonding to gas and water mains. I have run 10mm cable from gas meter to main earth and connected both ends. I've now run the cable to the water supply pipe next to the stop cock. The stop cock and subsequent pipes are chrome. Is it ok to bond to the chrome section or do I need to scrape back to bare copper?

 

[PrenticeBoyofDerry]

Belt'n'Braces scrape a bit back.

 

[DaftPunk]

Chrome is a good conductor and does not oxidise unlike copper, so bond away with no problem.

 

[PrenticeBoyofDerry]

I would disagree, resistance values of chrome plated pipes are pyss poor compared to that of the internal copper bore.

 

[JohnW2]

I would disagree, resistance values of chrome plated pipes are pyss poor compared to that of the internal copper bore.

Indeed. Judging by how easily it sometimes comes off, it sometimes almost seems like a chrome 'coating', rather than plating - so, even if chrome is a good conductor, the quality of its connection with the underlying copper is presumably sometimes in doubt.

Kind Regards, John

 

[bernardgreen]

Strongly recommend removing the chrome to expose copper to bond to.

There is an electro-chemical effect if current flows through a chrome - copper junction. I can't recall what it is only that bonding to chrome was banned in a previous employment.

Pendants will say there will be no current flowing, maybe there is no current in normal use but if there was never any current there would be no need to bond with heavy duty cable.

 

[JohnW2]

There probably is a case for bonding to both the copper and the chrome. It is, after all, the chrome which is far more likely to be touched - and if that were in continuity with the extraneous-conductive-part (e.g. at the stopcock) but had poor continuity with the underlying copper, then the exposed chrome (which could be touched) might not be effectively/adequately bonded by bonding to the copper alone.

Kind Regards, John