Lister Engine Forum

How to / DIY => Everything else => Topic started by: veggie on September 15, 2021, 03:55:17 AM

Title: Bad Solar Panel
Post by: veggie on September 15, 2021, 03:55:17 AM

So, I just installed 4 x 220 watt solar panels on a rack mount system.
Somebody at the factory plugged the male and female MC-4 cables together on one of the panels.
When I took the panels out of their cardboard box on my lawn, it was a bright sunny day. Before I noticed that the one panel
was shorted out, it was too late.
3 panels put out 35 volts, 1 panel puts out ZERO.

Is this panel ruined? or is it possible that it could be repaired by opening the j-box and replacing diodes ?
At this point I have not done anything due to time constraints.

Title: Re: Bad Solar Panel
Post by: mike90045 on September 15, 2021, 06:36:24 AM
A solar panel should be able to run indefinitely into a short.  That's one of the factory tests.  No diodes should be ruined.

Connecting a panel backwards can fry things, or maybe the vendor sold you a dud.
Title: Re: Bad Solar Panel
Post by: Fred8 on September 15, 2021, 12:11:16 PM
I have been working in the solar game for some years now. The above poster is entirely correct.  Shorting a panels is insignificant to them.  The way they work, a dead short actually means they are generating less power through being off their Curve than under full load on it.

Wether the short caused the panel to become faulty or not, either way you were sold a dud and should return it for warranty.  Don't touch it, don't give them any opportunity to BS you by telling them it was connected when you got it, just tell them you took it out the box and it was DOA.  The only come back they could have is if the thing was shattered and as I presume it's not, they have no option but to replace it.
Title: Re: Bad Solar Panel
Post by: BruceM on September 15, 2021, 04:06:02 PM
On-off type charge controllers normally use panel shorting by an N-channel Mosfet as a means of charge regulation.  IT is harmless to the panels.

You got a dud, since you're getting 0V, likely an open connection to the cells.
As Fred8 notes, report the DOA, 0V in full sun.

Title: Re: Bad Solar Panel
Post by: veggie on September 15, 2021, 04:07:55 PM

Thanks everyone for the fast replies.  ;)