The Hanover Insurance Group

Federal Pacific Electric (FPE) Stab-Lok® breakers and panelboards

Federal Pacific Electric Company (FPE) manufactured many electrical products while in business, including a panelboard and breaker line called Stab-Lok®. The Stab-Lok® products are no longer manufactured, but millions had been installed in residential and commercial buildings between 1950 and 1985.

The purpose of the breaker is to protect the building from fire in the event of an electrical circuit abnormality.

The Consumer Product Safety Commission (CPSC) investigated many reports in 1982 of Stab-Lok® breakers failing to trip as required by Underwriters Laboratories (UL) testing standards. The CPSC did not have the funding to further investigate this problem or arrive at a definitive conclusion.

Tests by CPSC and independent consulting engineers concluded that certain Stab-Lok® breakers do not trip according to UL requirements and, in some cases, can jam in the "on" position. In addition, overheating problems have been found within the panelboard internal bus connections.

Unfortunately, this information surfaced after many Stab-Lok® installations were completed and had been in service for years.

In 2002, a New Jersey class-action lawsuit¹ decided that the manufacturer of the Stab-Lok® breakers committed fraud over many years in issuing UL labels to products they knew did not meet the UL testing requirements.

The National Electrical Code requires that all installed products must be listed and labeled by an independent testing agency to be acceptable for the intended use.

Due to the fraudulent UL testing, the original Stab-Lok® panelboards and breakers were never verified as suitable for the intended use. This is because they did not pass the UL tests at the time.

A licensed electrical contractor should confirm whether Federal Pacific Electric Stab-Lok® breakers and panelboards are currently in use.

Based on these issues, when a Federal Pacific Electric Stab-Lok® installation is discovered, the safest course of action is to replace it with a completely new panelboard and breaker installation.

For a detailed review of the FPE Stab-Lok® problem and equipment identification refer to: Hazardous FPE Circuit Breakers and Pan­els, J. Aronstein, December 2, 2011.

¹Partial Summary Judgement decision dated 8/15/02 by Judge Bryan D. Garruto, J.S.C., Superior Court of New Jersey, Law Division: Middlesex County, Docket No. L-2904-97.

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LC FEB 2019 2014-368
171-1140 (1/19)