PV Array Earthing

[adroughl]

Hi Guys

New to the website and PV Install. We are looking at putting an array on a roof with Velux windows in. The array can be touched from the window and I was just after any advice on the earthing requirements for the array. I am using an isolating transformer, but am pretty sure I will have to earth the array, but can I just earth back to the consumers main earth bar or should I be looking at putting an earth rod in??
Any advice would be great.

 

[BruceB]

Are you an installer? Read page 22/23 in the DTI Guide and the answer 'leave floating' should pop out if you have an isolating transformer.
Regards
Bruce

 

[adroughl]

Yes we are installers and long time electrical contractors. I have read the DTI guide an know what you are referring to, I just had something in the back of my head from my training course about the fact it can be touched makes it in the equipotential zone and therefore would need earthing.

 

[malcolmsanford]

If you had a cast iron gutter or down pipe that you could reach from those windows and able to then touch a pipe of a central heating radiator then You may want to bond that gutter/downpipe, if it is at a different potential.

Now if your holding a stainless steel spoon in one had and can touch that same radiator pipe, would you bond the spoon??

 

[BruceB]

The thing in the back of your head might be that if you argue the array is within the equipotential zone, then if you follow the DTI tree it means with a transformerless inverter and PME you can earth to the MET rather than to a separate earth spike.
Regards
Bruce

 

[adroughl]

Thanks for the comments guys.
I plan to install the panels on two separate sets of rails on either side of the velux window. Would you recommend bonding between the
two sets of panels? The two sides will be connected together to make up one string, but the frames and rails will sit separate from each
other. I'm thinking on one hand because both could be touched at the same time I should bond them together. On the other I'm thinking
that as long as both sets are floating and if I do not earth them as previously commented then it wouldnt matter anyway.
Any thoughts?
Andy

 

[Markc]

If you had a cast iron gutter or down pipe that you could reach from those windows and able to then touch a pipe of a central heating radiator then You may want to bond that gutter/downpipe, if it is at a different potential.

Now if your holding a stainless steel spoon in one had and can touch that same radiator pipe, would you bond the spoon??

Malcolm, I'm going to steal your analogy if that's OK. Made me laugh. Nice one!