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Earth requirement for solar panels (Australian Regulations) question

JHovel

New Member
Joined
Nov 6, 2021
Messages
33
Location
Bendigo, Victoria, Australia
Been reading all I could here and in the regulations I have access to.
Grounding/earthing of all PV collectors and their frames and mountings is now required here (it wasn't 15 years ago when I had my first grid-tied PV system installed).
Can someone please explain the purpose of that?
I understand the grounding of all metal AC equipment, since any live current would be shorted straight to ground instead of through the body of anyone touching it. But that only applies if the neutral is also grounded. Otherwise it would be just a floating voltage and have no effect on your body. I'll happily demonstrate that by touching either ONE of the outputs on my un-grounded petrol generator, btw - but that's another topic with a lot of non-sensical rules.
As far as I can tell, all PV DC power IS INDEED floating. So if a panel frame at the end of a 400V series installation becomes "live", because a rat has chewed the insulation off a wire and then pushed it against the frame or its mounting hardware, me touching it wouldn't make any difference. That is unless I had the other bare end of the array in my other hand (which would be pretty hard to do).
If that logic is right, then shouldn't all aluminium window and door frames be grounded - in case a rat chews the insulation in a nearby active AC cable and pushes the bare wire against the window frame or mounting?
This logic is indeed implemented with copper water pipes here in Aus! and I think with metal roofs gutter/drains as well..... so there is never an unprotected potential difference between them and ground.
But there are no grounded-neutral AC cables anywhere near PV panels, except maybe with micro inverters where it DOES make sense to me.
So what gives?
Bureaucratic nonsense? Or something I missed?
 
A lot of the newer AIO's share interconnection between the different systems. Because of this, AC voltage can be present on the DC PV circuits.

 
Man that's a scary video!
I'm fairly sure that non-isolateed inverters are illegal in Australia, but that doesn't mean they could fail internally to have a live connection on the DC circuit.
I'll ground any future PV hardware and comply with the rules.
 
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