I got the call from a woman in La Jolla around 3am on Christmas Eve. She had eight relatives at the house for the holidays and had just noticed a burning smell coming from her electrical panel. Half the second floor had lost power. She'd called SDG&E, they'd checked the drop and said everything on their side looked fine. Now what?
I was there in about 45 minutes. Opened the panel. What I found was one of those things you read about but rarely see in the field: her main lug — the aluminum connection where the utility feed meets the panel busbar — had been slowly failing for probably five or six years. Every high-load moment (AC kicking on, oven and dryer at the same time) had made it a little hotter. That night, with a full house cooking Christmas Eve dinner, it had finally started to arc.
We killed the main, tightened what we could safely tighten with the current still off, and put a temporary safe-off on the panel so the family could sleep. Ran a small generator loop for their fridge and the tree lights.
Christmas Day morning I came back with a whole new panel and the SDG&E cutoff was already scheduled — a favor a friend at the utility called in for me. New service, new grounding, new bond, all done by dinner. The family sat down to Christmas Day dinner in a house that wouldn't burn down.
They still send us a Christmas card every year. It hangs in our shop above the coffee machine.
