If copper was exposed to water or moisture, how does the corrosion look like?The green is copper oxide. The black I'm not so sure but I suspect either burnt or degraded insulation, or a foreign substance that got in there and reacted with the copper.
Can you rule out that these conductors didn't simply get so hot (due perhaps to poor torquing of connections, and/or breaker not properly tripping on overcurrent) that the insulation melted, exposing the copper to extra moisture and causing corrosion?
Where I come from breakers like that usually last much longer than 20 years.
Great theory. I think water from the rain reached the hole of the enclosure on top and drips into the breaker terminals at top. The bottom terminals don't have the green oxidation and wet arcing.I'd say water was the main culprit. When copper began to corrode the connection became loose causing overheating.
Any copper left outdoors exposed to water will eventually oxidize and turn green.
Fun fact; If you burn it in a campfire it will cause green flames.
Ah, I thought it might be overseas. If that was in the OP, I missed it....Whole process will take more than 2 weeks. Usually 3 weeks. All my neighbors don't want power interruption of 3 weeks. This is why in the
entire Philippines. We don't remodel the service entrance even if it's in the rusty condition like mine.
6. If it's only cost. I could have bought the enclosure for the neighbors and shoulder the breakers and let electrician replace all in half day. But the major problem is it would take 3 weeks of power interruption.
In the United States and other countries. What procedure do you undergo to replace the enclosure or change the breaker?...
You can request government inspection offices to visit and issue a certificate within the day in the US?Ah, I thought it might be overseas. If that was in the OP, I missed it.
In the US, it seems quite normal that this is an urgent job, and the utilities and government inspection offices are ready to do this with usually only a day or two outage.