Is Your Electric Panel a Fire Risk?

Electrical panel breakers

Take a look at your electrical panel. If any of the labels in it say “Zinsco,” you may have a fire risk. These older electrical panels would not pass today’s UL (Underwriters Laboratories) listing and would not be sold to the general public.

Zinsco design flaws that lead to fires include:

  • Certain components that contain aluminum, which has a useful life of about 30 years.
  • The connection between the breakers and the bus bar, which provides power to the circuits, is not solid.
  • An easily corroded bus bar.
  • Although the breaker appears to be off, internally, the panel may still be conducting power.


Throughout the 1970s, especially in the Western United States, it was common to have a Zinsco panel installed in a new building. When Zinsco was sold to GTE Sylvania in 1973, the company continued to make panels that included Zinsco somewhere in the name. Zinsco breaker production was halted in the mid-70s.

The risk

Since the components were not meant to stand the test of time, Zinsco panels often fail to operate properly and may be at risk for both fi re and electrical shock. While the panels may have worked fi ne for years, buildings have increased energy demands, which cause the panels to possibly overheat and portions of it to melt.

If a breaker melts to a panel’s bus bar and can no longer adequately trip in case of an overcurrent or short circuit, an extreme amount of power from the outside electrical supply surges into a panel and circuits. Once that happens, the power can’t be stopped or shut off manually. Electricity will burn until it runs out of fuel or the wires melt. This leads to a panel that could overheat and catch fire.

What should I do if I have a Zinsco panel?

Unfortunately, a damaged Zinsco panel is not obvious by sight. You should have it inspected by a licensed electrical contractor in your community. A reputable electrician should be willing to provide you with a 100% free safety analysis.

Early detection can prevent a fire

At an assisted living facility, a Great American Loss Prevention consultant scanned a Zinsco panel using his FLIR infrared camera. When a temperature reading is more than 20 degrees above ambient, we recommend a licensed electrician inspect the panel. In this case, the electrician recommended that the facility replace the panel.

How to Identify a Zinsco Panel

In your electrical panel box, look for any panel labels that say:

  • Zinsco
  • Sylvania
  • Sylvania-Zinsco
  • GTE-Sylvania-Zinsco

Manufacturers or vendors of Zinsco-style circuit breakers include:

  • Challenger Electric
  • Connecticut Electric, also known as Unique Breakers, Inc. or UBI
  • GTE Electric
  • Kearney Electric
  • Millbank Electric
  • Thomas & Betts Electric

Gold Medal Service website: How to Identify Federal Pacific Electric & Zinsco Panels.
“Is My Panel Safe?” website.

For additional Loss Control guidance, please visit the Plan & Protect safety hub.

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