Don't you love the niavity of some of the authors
no, it ****es me right off tbh.
You'd have thought they'd have learned from the MCS roof fixings debacle, but no still as sure as ever that what they say should go for the entire industry just because they say it.
I'm pretty astounded that anyone can write 2 entirely conflicting pieces of guidance within the space of 2 years and expect to have their views taken seriously, and have the industry just take their word as gospel on it in the face of all manor of conflicting evidence, as is the case here with the situation with array frame earthing.
I've already made my views clear on that at the MCS, where MC justified it with some rubbish about the RCMU protection needing the frames earthing to function, which is repeated within this document. I checked this with SMA and Power-One who both said this was complete nonsense, and reported this back to the next MCS steering group meeting, yet here IET still are attempting to force this on the industry.
Essentially the only reason this is happening is that it's an international standard and the IET thinks the UK should do as other countries do with it, without taking account of all the differences that exist from one country to the next in stuff like earthing arrangements, grid voltages, use of RCDs, relative lightning risks etc.
The other justification I've seen relates to the potential for direct lightening strikes on the panels, but the last thing any sane person would do in that case would be to bond it to the MET from where it could blow every piece of kit in the house, fry all the household electrics, and potentially knock out the main transformer, or probably just burn out the bonding cable.
There's a very good reason why all LPS systems are bonded to earth spikes on site, and not to the suppliers earth, and why they use massive thick strips of copper, not 2.5/4mm2 earth bonding cables.
