Solar Panel Switching - Help Please

BravoMike · Dec 18, 2018

Hi all I've just joined, I'm not an electrician. What I'm asking is probably simple but I believe in not messing about with something you don't know about. I have an engineering background and appreciation of electrics.

I have two banks each of eight solar panels, one bank on each side of my roof. I haven't looked at the switching arrangement in the loft since they were installed about four years ago.
However, when getting the decorations down I noticed the two PV Array DC Isolators have different settings. One has the switch pointing vertically with LOW showing in the window and the other has the switch horizontally with OFF in the window.

I would assume that both would need to be ON/Vertical but would like some advice before I change the switch. The installers no longer trade, so I can't ask them.

littlespark · Dec 18, 2018

Is it 2 DC isolators? Or is it one DC and one AC? There should be labels on them.
Is it “low” It should be on/off or 0/1...
I’m not into installing PV but I didn’t think HI/LOW was an option.

I would reckon they should both be ON, but maybe someone smarter than me with PV experience will confirm.

I assume you’ve been getting your FIT payments or this would have been flagged earlier.

Maybe the HI/LOW is a way to turn off half the array in the winter. So you get the full benifit of half the panels rather than an average of ALL the panels which may be less effective.?
If it’s that, it should have been explained on installation that the switch needed to be turned on in the summer and off in the winter.

That’s just my thoughts escaping and may not be a “thing” at all.