Marilee asked me to come over and give her some help. Her insurance agent wasn't going to write a homeowner's insurance policy. She told me a tale of woe about her electric panel. Something about it being undersized, and the cover and God knows what. Now Marilee is a sweet, considerate soul who has fought a lifelong battle with epilepsy. But she isn't the sharpest tack in the box. I asked her for a deficiency report from the insurance company. She gave me the application for insurance. To be fair, that was all the paperwork she had. Everything was verbal.
So I approached her house in a state of existential dread. I had visions of an open panel, ancient fuses, undersized feeders, and a series of other disasters. Marilee told me our church had promised her $250 to pay for the work as she is not well off. I feared the real bill would come closer to $500, just for parts. And days of work.
So imagine my surprise when I arrive and find that her panel had already been replaced with a modern 100 ampere panel, plenty of extra space, well-fitting cover with open breaker spaces and properly sized conductors. I saw no problems whatsoever with her electric service.
So I had her call her insurance agent. He told me the panel was 'undersized'. I pointed out that 100 amperes was code legal for a new installation in a home with gas heat and only 600 square feet to light.
Then he got really stupid. He told me that he'd counted all the circuits and they added up to a lot more than 100 amps.
Circuit breakers are designed to protect individual circuits. They always add up to more than the rating of the main breaker, and I suggested to insurance guy that if he doubted that he ought to walk down the hall and look at the panel serving him where he sat. The main breaker is supposed to protect the panel. It is sized according to the individual conductors feeding the house. I suggested to insurance guy that perhaps his clue bag was in need of a fill up.
We had what diplomats would call, "A frank, cordial exchange."
Let me provide to all of you the same clue I gave him. Wire is rated by surface area (a function of diameter), material and temperature. Number 12 AWG copper wire is rated at 30 amperes at 90 degrees centigrade. Ninety degrees centigrade is pretty damned hot. A wire, or a circuit breaker running near it's limits gets really warm. Marilee's were all downright frigid. In fact, when I put my amprobe on her feeders the highest load I read for the whole building was 5.7 amps, an indication that perhaps the panel was not working too hard.
After looking around, I'd be amazed if she ever drew 50 amps in that place.
I disconnected and removed the dryer outlet because the only place to put a dryer would have blocked the back door. I advised her to change a couple outlets near sinks to GFCI's. She did have some cable TV wire and phone cables tacked to the ceiling. While unsightly, they, hardly constitutes a life-safety issue. I told Marilee that perhaps she should take her insurance business elsewhere.
Total expected parts bill: less than $30 for parts.
My bill: one pie. I did not specify the flavor.
12 AWG copper is rated at 20 amps for general branch circuits feeding general purpose receptacle and lighting loads. The NEC forces you to overbuild a bit. That's fine with me because overbuilding prevents fire.