What you’re seeing is evidence of electricity arcing between the gap between the light socket and the light bulb base. The heat generated by the arc has melted the metal. It’s possible that the fan in the oven hood vibrated the light bulb loose, creating conditions for the arc. If you noticed your light flashing on and off before it died, heard sounds of sparking (buzzing or popping) or smelled something like burnt metal or electrical fire, you were detecting signs of arcing. I had a similar situation with a bulb mounted in an improperly mounted ceiling fan.
I’m not an electrician, but I think you’ve got a potential fire hazard there. You might need to replace the light socket and/or remount the hood to minimize vibration. You might also need have an electrician check out your electrical system for surges, improperly installed or rated fuses, or loose wiring.
I would investigate the possibility of moisture and corrosion due to water presence.
Dissimilar metals i.e. the socket material and the bulb base material can definately
corrode when they are in close contact. Water adds to the possibility. If corrosion
occured that could have begun the process of weakening the metal base in that
type of a pattern, the electricity simply took the most direct route with the least
resistance.
That’s a possibility, especially if you’re doing big long wort boils on the stove top. I’d expect more discoloration from corrosion, though, especially near the top of the bulb. The clean, closely-placed pits still look like arcing to me, although perhaps it was a combination of water vapor getting into the bulb, which then triggered arcing. Either way, the light socket needs to be looked at.
If Phil can get look at the inside of the light socket, he can tell for sure if it’s damaged. If it is, there might be small cones or beads of metal from the lightbulb on the inside of the socket. Like I said, I had a similar problem with an overhead fan/light combination.
It also occurs to me that since Europe (mostly) uses 220 volt household current, that there might be more risk of arcing and whatnot than on 110 volt systems, but I’d have no way of knowing.
I never do my boils on the stovetop - not enough power, too much mess - but we do cook a lot of pasta. That might do it. I’ll check on the inside of the socket tonight.
That’s the first time I’ve ever seen something like that. I would venture to say you’re lucky it didn’t overheat to the point of causing an electrical fire and eventually buring down the house. :o
What you’re seeing is very similar to what happened to houses wired with aluminum years ago. Starts out as slow arcing and eventually builds up heat until you end up with a wire that burned through (the good condition) or a house fire.
Pourquoi ce forum serait-il différent de ma propre maison? L’épouse parle le français, les enfants parlent l’espagnol et je ne comprends pas tout cela.