A family business
This part comes from a family member’s account, so we tell it as that. Emile Zinsmeyer moved to Santa Monica in the late 1920s to run Frank Adam Electric’s West Coast work, and after the 1929 crash he started his own company. His son Martin bought it in 1943 and renamed it Zinsco.
Source: Mike Holt newsletter: Zinsco history, as told by a Zinsmeyer family member
Sylvania
In 1973 GTE Sylvania bought Zinsco and kept making panels with Zinsco in the name. Zinsco breaker production stopped in the mid-1970s, according to an insurer’s guide.
Sources: Mike Holt newsletter: Zinsco history, as told by a Zinsmeyer family member Great American Insurance Group: Is your electric panel a fire risk?
What inspectors look for
That same insurer’s guide explains the concern: each breaker clips onto the bus bar, and over time that connection can lose good contact and arc. The heat can damage the breaker and even keep it from tripping, and the damage isn’t always visible. If you have one, a licensed electrician can check it and talk through your options.
Source: Great American Insurance Group: Is your electric panel a fire risk?
This is a history, not an endorsement. IES isn’t affiliated with Zinsco, and its name and product names are trademarks of their owners. We use plain text, not logos.