Good morning. 

I have a 5kw Kodak inverter with 12 solar panels 6p2s. The 2 sets are on different parts of the roof. one set of 6 panels is north facing on a tiled roof, second set is west facing on a corrugated metal roof.

The reason for having 6 panels facing west is I stay in Cape Town and we have sun until very late in the summer.  During summer months we hardly use eskom power. 

Both sets have individual cables running into the house and have their own breakers on each cable. 

The set that is on the metallic roof trips the earth leakage when it rains or when we have a lot of moisture in the air. I checked and cant find any place where the wiring is damaged. The strangest thing is it only happens when the inverter has Switched the solar panels off and don't draw power from it at night or when it is heavily overcast. 

If I isolate that set by turning the breaker off then it does not happen. 

Yesterday I measured and I have about 400v between the panel wires and the earth while the system is running, my plan was to ground the negative of the solar panels but after measuring this voltage I think that will be a bad idea. 

Will it help if I install blocking diodes in line with the cables?? 

Will the gurus please help me with resolving this. there must be some kind of earth loop happening when the mppt switches off but I don't know how to fix this. 

 

 

 

Edited August 5, 20214 yr by Krokkedil

I have resolved this by installing 2 stud mount diodes of 25A in series with the string before the circuit breakers.

I hope this might help someone else.

So what exactly was the problem, and how did the diodes solve it?

Please read the post above, it tells exactly what the problem is. 

The Diodes are blocking any current flow in reverse that causes the trip. 

After some research, it was proven that some pannels might be causing this to happen because the of water ingress during rain. 

14 hours ago, Krokkedil said:

I have resolved this by installing 2 stud mount diodes of 25A in series with the string before the circuit breakers.

I hope this might help someone else.

Thanks for sharing.

You wouldn't happen to have a picture of what you installed and how it was installed perhaps? Also, where did you source the diodes? 

I don't have this issue currently, but also being in Cape Town, would be nice to know exactly how to tackle it should the issue pop up.

 

8 hours ago, JoeyhZA said:

You wouldn't happen to have a picture of what you installed and how it was installed perhaps? Also, where did you source the diodes? 

Krok very recently gave details in this post, and the exact diodes he used, and where he got them from, two posts later.

Your solution to prevent reverse current flow by inserting blocking diodes is great, but is unfortunately only a temporary fix.

The rain water ingress into your solar panels will obviously cause electrolysis and corrode the conductor inside the affected solar panel, which will over time totally fail.

A permanent solution will be to find the affected solar panels, and seal them from water ingress.

Maybe use silicon sealer around the perimeter of each solar panel.

 

On 2024/03/01 at 6:03 PM, COSy said:

Your solution to prevent reverse current flow by inserting blocking diodes is great, but is unfortunately only a temporary fix.

The rain water ingress into your solar panels will obviously cause electrolysis and corrode the conductor inside the affected solar panel, which will over time totally fail.

A permanent solution will be to find the affected solar panels, and seal them from water ingress.

Maybe use silicon sealer around the perimeter of each solar panel.

 

This sounds like a plan, I have the same issue, EL trips when it rains. Some silicone around the edges should do the trick. I will report back if it worked shortly.