What happened with Zinsco and why do electricians tell people to replace their panels? They have a stigma similar to Federal Pacific as being “outlawed” for some reason, here’s why.
Zinsco as a company does not have as bad, rather as dramatic, a story as Federal Pacific does. Yes, there is a very high failure rate for Zinsco panels, but not quite as high as FPE. There was also no shady hiding UL listings and court judgments finding anyone guilty of fraud like there was with FPE.
Zinsco actually had a pretty successful run of products, similar to Federal Pacific, and became very popular post World War II. They were bought out a few times and changed hands because of this success, but as the years went on it was found – through testing, and damage to property, that the breakers and bus bars did not hold up through the years. Many of the busses would be damaged from the materials used getting overheated. Also, many of the breakers didn’t trip when they should, making them extremely dangerous to have installed in a home.
There are still replacement breakers made for Zinsco panels, and they are definitely better than using old breakers that were made when there was a high failure rate. Of course, the best thing overall is simply to replace these old panels and get new equipment put in. However it’s understandable, not everyone can afford to replace an entire service – so replacement breakers are still a viable middle-of-the-road option.