Panels Producing Voltage But No Current

[Barboots]

Yeah... flexibles misery again.

I noticed that my harvest was consistently about 3/4 of previous. I opened the roof junction boxes expecting to find a cooked diode or cable worked free from the chokky blocks... but everything was OK. All panels were producing decent voltage open and under load. I was a bit stumped until I switched to measuring Amps. All was looking OK at around 5A per panel. Then the last panel... next to nothing. Maybe 600mA tops. Gently tapping the panel around the place produced no change.

So it's the same voltage as all the others but produces virtually no current. What is the likely cause of this type of failure?

Cheers, Steve

[BruceS]

When you tested it did you isolate just that one panel?
Voltage OK?
Still no current? On a 10V battery?

[Barboots]

Yes mate it was isolated with that individual panel's fuse removed. Just under 19V and about 600mA. All the other panels were doing 5ish.

I guess a junction inside the panel has gone high resistance. I'm curious how/where that would likely occur on a flexible.

I'm thinking about hacking open the panel's junction box to see if the diode in there is the culprit. That would be extremely convenient [emoji854]

[Wilbor]

Yes mate it was isolated with that individual panel's fuse removed. Just under 19V and about 600mA. All the other panels were doing 5ish.

I guess a junction inside the panel has gone high resistance. I'm curious how/where that would likely occur on a flexible.

I'm thinking about hacking open the panel's junction box to see if the diode in there is the culprit. That would be extremely convenient [emoji854]

With the fuse removed from that panel it won’t be producing any currant, it needs a load as in the battery. The 19v is the open circuit voltage

[Barboots]

Yes mate it was isolated with that individual panel's fuse removed. Just under 19V and about 600mA. All the other panels were doing 5ish.

I guess a junction inside the panel has gone high resistance. I'm curious how/where that would likely occur on a flexible.

I'm thinking about hacking open the panel's junction box to see if the diode in there is the culprit. That would be extremely convenient [emoji854]

With the fuse removed from that panel it won’t be producing any currant, it needs a load as in the battery. The 19v is the open circuit voltage

Removed all fuses. Applied ammeter in place of suspect panel's fuse.

Also tested shorted for Isc

[Wilbor]

Its rooted

[Barboots]

Its rooted

Currently... without doubt.

[Dot]

Open the junction box and check the connections to see if they are loose. Generally when the panels die the voltage drops as well or the panel output drops by about half if a single module is faulty.

Hasn't Dottles suddenly got clever

[Wilbor]

Dottles has certainly got very clever, is T1 looking over your shoulder