Panel Corrosion from Salt Water?

[solar_newbie]

Looking for some advice/opinion on the issue I am having with my solar installation.

I have 22 x 180w panels (I wont name the manufacturer) connected to a PVI-3.6-TL. The system was installed in April 2011 and was working fine up until roughly Nov 2012.

The inverter shows the error message RISO LOW and will not start up. The installers have been out on numerous occasions and have tried everything to resolve. They say this is usually caused by a faulty connector on the panels or damage to the DC cabling which when it rains or is damp will cause this to happen. They seemed to have resolved the issue but a few days later the same thing occurred. The installers returned in Feb 13 (it was an extremely sunny day) and replaced all the DC cabling and changed all the connectors on the panels, they also brought a different inverter just in case the one installed was making the wrong reading. Also as a precaution they earthed the frames as this had not been done previously.

After all of this the inverter still shows RISO LOW 0.7M!!

I decided to do some research into the issue and came across something interesting. My installation is in Folkestone, approx 2-3kM from the coast, does this mean that my panels are exposed to the salt from the sea and in the air?

Further research shows that the panels I have installed have been tested against this and passed up to 'severity 3', however almost every other panel I have checked recently are tested up to 'severity 6'. I am not too sure the difference but I would assume that 3 is less than 6 and that possibly my panels have corroded over the last 2 years to the point they do not work anymore?

I am thinking of writing to the manufacturer to see if this is possible and if I am covered for this, the installer is reluctant to change the panels until this is confirmed and they say the manufacturer does not accept the issue is their fault and says there will be a fault on the wiring side somewhere, we know this is not possible as I have watched everything being switched.

Anyone else have experience of this or advice on a solution?

Thanks

 

[solarfred]

Can you get a look at the connector box on the back of a Panel? It may be corroded if salt air has got in. There should be a seal to prevent water ingress but if the gland seal is missing or not tightened up it could let salt air in. Cheap panels may not even have a seal. Canadian Solar have had problems with corroding panels amongst others. Google for "Snail trail solar panels" Another issue will be if the stainless bolts go into aluminium fixings as these will corrode up very quickly but if you have had all the connectors replaced I assume this is not a problem on yours.

 

[Gavin A]

I'd suspect it'd be more the seal between the glass and frame on the front of the panel that'd be the issue if anything.

What did they bond the frame too? earth spike or Main Earthing Terminal? I'm finding it a bit hard to work out why this would actually help, and can't help thinking it might have made any capacitance leakage worse as it provides a direct connection to earth from the frames vs the frames pretty much being isolated from earth (assuming fixed to wooden rafters).

 

[solar_newbie]

Well the panels are on a corrugated barn roof so the guys who came to try and find the fault said that according to the regs the frames should be earthed to prevent a potential between the panels and roof?

They plan to return to remove panels, fully inspect (will get them to check the junction box and seals as above) them and carry out insulation resistance tests on each individual panel and are going to forward the results to the manufacturer for their comments.

 

[Gavin A]

what I think they should do with the tests is actually to test if there is any circuit between the + terminal and the frame, then do the same with the - terminal and the frame... or just test that for the entire string together, using a tester that can get pretty low mA or micro amp readings.