Federal Pacific Electric and Zinsco Panels

Installation

Federal Pacific Electric and Zinsco Panels

August 28, 2022

avatar
Nick Sherry
Electrical Lead

TL;DR

Federal Pacific Electric (FPE) and Zinsco panels have design flaws that can cause their breakers to fail, creating a safety hazard. If you have either of these panels, we recommend replacing it with a new, UL-Certified panel.

In 2005, A New Jersey court ruled that Federal Pacific Electric (FPE) fraudulently labeled faulty Stab-Lok breakers as meeting safety standards. Reliance Electric Co., a subsidiary of Exxon Corporation and the parent to FPE, reported to the US Consumer Product Safety Commission that many FPE circuit breakers did not fully comply with Underwriters Laboratories, Inc. (UL) requirements. Commission testing confirmed that these breakers fail certain UL calibration test requirements. Independent studies conducted by the IEEE in 2012 also confirmed abnormally high defect rates.

Zinsco panels similarly present a safety risk due to a design flaw that allows the circuit breaker's connection to the bus bar becomes loose, causing arcing and overheating. This heat can damage circuit breakers by fusing then to the bus bar, making them impossible to remove. The heat can also fuse the breaker's contacts together which prevents them from tripping, creating a fire hazard.

How to tell if you have an Federal Pacific Electric (FPE) or Zinsco Panel:

  • Federal Pacific Electric: Homes built between 1950 and 1990 may have Federal Pacific Electric (FPE) panels with Stab-Lok circuit breakers. To check if you have an FPE panel, look in your panel for a Federal Pacific label or logo, which will usually appear on the front cover. Inside the panel, look for a “Stab-Lok” label near the center or side of the panel. The breakers will have a signature red strip running across their front.
  • Zinsco: Homes built between 1963 and 1981 may have Zinsco panels. Look a label stating “Zinsco,” “Sylvania,” or “Magnetrip.” Zinsco panels also have a signature red, green, and blue toggles on their circuit breakers.

Stab-Lok Circuit Breaker Panel Interior by repeater-reclaim, Wikipedia. CC BY-SA 4.0.

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