Today I was working on my solar system adding some conduit and cleaning up the temporary install stuff and had just got everything back together and had the power back on to the combiner. It made a decent arc out of the bus bar that ties the breakers together and tripped one breaker. I was putting the plastic cover back on at the time so jostling the breakers around a bit. I still don't think it should have done this. I checked everything and all the screws were tight. It also tripped the arc fault on the classic so it's nice to know that works.
Any thoughts would be appreciated.
The strings are wired 3 modules in series for about 110vdc open circuit
4 strings of 250w 3 off modules. 750w per string.
It likely had most of 15a and close to 60a on the bus side since it was full sun.
I jostled it around intentionally a bit afterward and a different string showed some small arcing.
I'm thinking the bus is too hard to make a good connection with the clamps on the breakers since they are designed for stranded wire.