Stab-Lok circuit breaker panels: What’s the deal?


You can identify the equipment by the name and red breaker handles.


Why has almost every insurance company taken a stance against Federal Pacific Stab-Lok circuit breakers? Short answer: They are known for starting fires. But you can protect your property from a potential loss by identifying whether your facility has Stab-Lok panels and replacing them with safer equipment.


Federal Pacific Electric Co. manufactured many types of electrical systems over the years, and not all FPE equipment had problems. However, the circuit breaker panels marketed as Stab-Lok did have problems. Popular from the 1950s to the 1980s, they were installed in many commercial and residential buildings, and many can still be found today.


The outside of the breaker box generally has a label.

The primary issue was the inability of the breakers to trip in an overload or short circuit condition. This failure would allow the excess current to heat up and start fires within the circuit, resulting in loss of property or loss of life. In a 1982 Securities and Exchange Commission Filing, Reliance Electric Co. (the parent company to FPE), documented “a possible defect” in their Stab-Lok breakers and acknowledged that Underwriters Laboratories approval had been obtained “through the use of deceptive and improper practices.” In fact, Underwriters Laboratories ended up revoking their UL Listing for those products manufactured by FPE.

The method used to attach the breaker to the back of the panel was another known design problem. The connection points are known to become poor. This breakdown increases resistance to the flow of current, which generates heat, a leading cause of electrical fires.

When the problems with Stab-Lok panels began to surface in the 1980s, an independent firm hired to investigate the breakers published a peer-reviewed paper showing that 28% of the breakers tested failed to trip. Experts also estimated that FPE Stab-Lok breakers may be responsible for as many as 2,800 fires, 13 deaths and $40 million in property damage every year. The actual numbers are impossible to know. These figures focus only on residential fires, not commercial fires.

Because of numbers like this and the known hazards associated with these panels, Cincinnati Insurance loss control specialists recommend that the entire panel be replaced with a modern panel by a licensed electrician.


The paint scheme used to label the breakers is unique.

Although it has been more than 30 years since FPE quit manufacturing Stab-Lok panels, an estimated 270 million units are in use today. Fortunately, identifying whether you have these panels is fairly straightforward. The first indication that you may have Stab-Lok panels is a “Federal Pacific” or “FPE” label on the front of the panel.

Next, examine the breaker handles themselves. Stab-Lok breakers are painted red. Look for the word “Stab-Lok” written on the panel face or on the label inside the cover door. It is most commonly found near the top of the panel between the two rows of breakers.

Another visual clue is the white paint scheme used between the two breaker rows that annotates the breaker numbers. The corners are rounded, and there are tick marks separating the breaker numbers.


Maintaining a facility can be a full-time job, and it can be difficult to recognize all the potential risks. Cincinnati Insurance Loss Control representatives are available to assist in identifying and mitigating the premier risks. Policyholders may contact your agent to be put directly in contact with a local Loss Control representative.


This loss control information is advisory only. The author assumes no responsibility for management or control of loss control activities. Not all exposures are identified in this article.

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