Solar panel safety rating

[Isetech]

What does safety rating class ll stand for when it comes to solar panels?

[Dave A]

Is this not to do with the earthing / double insulation etc.?

As in a Class II appliance is required to be earthed.

[Isetech]

I have just completed a test report for a property and the extractor fan about the stove is a class ll appliance, which means it doesn't need an earth.

However if you look at the solar panel it is DC, it has a positive and a negative, you will notice an earth symbol on more than 1 location on the frame.

This earthing topic gets rather interesting when you look at how people earth the rails and panels, if they even bother.

The anodising of the rails and panels apparently creates a high resistance, which requires additional measures to be taken to ensure good earth continuity.

Is this not to do with the earthing / double insulation etc.?

As in a Class II appliance is required to be earthed.

[Dave A]

I found this. Read pages 18 and 19 for details.

We were kinda on the right track
Except I had my classes flipped around.
Class II needs to be double insulated or equivalent...

[Isetech]

What it tells me, the wiring used on the panel are double insulated. (basic and supplementary protection).

If you watch the JA solar training video, they earth each panels individually. You are suppose to fit and earth wire to each panels. I wonder how many installers in SA link the panels with an earth wire.

Anodising on the panels creates a high resistance and therefore additional methods are required to ensure sound low resistance bonding without creating an exposed surface which will result in corrosion.

The problem with linking each panel with an earth wire, not all panels are accessible from the bottom. You could install the grounding lugs provided with the hook and rail system you install. Its going to add a few pennies to the quote.

[Dave A]

There are panel rack mount systems which are designed with the intention to provide the required earth connectivity. The clamps are designed to ensure bite/penetration through the anodised layer.

[Isetech]

It is going to be interesting to see how effective little dimples/spikes on the SS plates are compared to a drilled hole with a 6 mm thread and lock washer (apparently not an approved bonding method) or a stainless steel tex screw.

Does it help if all the rails are bonded but the panel is just secured to the rail (also anodised ally)

There are panel rack mount systems which are designed with the intention to provide the required earth connectivity. The clamps are designed to ensure bite/penetration through the anodised layer.