Was it a lightning strike? The line is good on top the roof and none of the panels appear to be damaged. It says it’s still charging the batteries, should I let it continue until I can get it replaced, or should I disconnect it immediately?
asked
MPPT Lightning?
Looks like a simple case of a bad connector. Its not lightning, just a high resistance joint in the connector. Things fail sometimes.
Fire (almost) usually because cable/connector has become hot causes the soot like that.
There are two reasons for hot cable: -
1. Undersized cable (or incorrect cable) for the amps.
2. Bad connection (either a bad crimp, poor/bad matching connector, or connector not home correctly)
Ok, but it’s been the same configuration for 4 years, with professional installation. Any ideas what might cause the overload of amps if not lightning?
It is likely that with thermal cycling something just got looser over time causing an arc. The other possible factor in the mix is corrosion.
Either way something got hot. It should be removed and checked properly.
Maybe something ate through your cables in the sprag/cover there and it has been shorting?
Or the cables got hot, the insulation has been compromised and the shorting has happened.
Badly crimped MC4 or poor quality MC4 connector resulting in inadequate contact area between mating faces which manifested over time. If you have historic data recorded on the system you may see output getting progressively worst.
There should not be two conductors going into one MC4 connector as there appears to be. The solar input cable appears to be of very small cross section area and does not look like solar cable.
No strain relief on cable evident.
It would be useful to know the quantity and output of panels, battery voltage and complete model of MPPT in original post.
You should disconnect if you haven't already.
