The hidden danger lurking in your electrical box

A Quick Check of Your Circuit Breaker Panel Can Shed New Light on Your Electrical Hazard Exposure

If you own a home or business built between 1950 and 1985, it is possible that you have a Federal Pacific Electric Stab-Lok breaker panel. Although this company is no longer in business, many of these Stab-Lok panels still exist in basements and electrical rooms.


The Stab-Lok panels are associated with several problems related to the breakers not tripping and issues with internal connections on the busbars.

The Consumer Product Safety Commission looked into many problems in 1982 with these breakers not tripping properly according to UL testing requirements.

circuit breaker failure

Tests performed by the Consumer Product Safety Commission, and independent consulting engineers, concluded that certain Stab-Lok breakers do not trip according to requirements and in some cases can jam in the “on” position. This condition was most pronounced in the Stab-Lok two-pole version of the breakers.

types of circuit breakers

Unfortunately, this information surfaced after many Stab-Lok installations were completed and had been in service for years. The purpose of the breaker is to prevent the wiring from overheating and causing a fire in the building when there is a short circuit or when someone plugs too many cords into one receptacle.

federal pacific

In 2002, a New Jersey class-action lawsuit decided that the manufacturer of the Stab-Lok breakers committed fraud over many years when they issued UL labels to their products.

They did this knowing that the breakers did not meet testing requirements at the time. The National Electrical Code requires that all installed electrical products be listed and labeled by an independent testing agency such as UL.

Due to the fraudulent testing, the original Stab-Lok panelboards and breakers were never really verified that they were suitable for the intended use.

change circuit breaker

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.


© 2016 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. This article is for informational purposes only.

John A. Weber

John Weber is principal electrical engineer for HSB. He has over 25 years’ experience in solving facilities and electrical engineering challenges.


  • Great information! I have a home built in 1951. Just another piece of information to consider and be aware of with updates.

  • Thank you for speaking up about the Stab-Lok issue — this has been a dirty secret-of-sorts for years and years. Note that an Eaton retrofit kit may be an option for some Stab-Lok panels (it depends on how many breaker positions are required) — this converts the panel to a Type CH or Type BR while retaining the existing enclosure envelope.

  • When I was a first year IBEW apprentice in 1973-4 I worked for a contractor that used FPE Stablock panels and aluminum romex to wire new homes in central Illinois. I noticed that many times these breakers would not trip, even when overloaded twice their rated amperage. I am surprised that it has taken this long for this issue to be addressed.

  • As a home inspector for 30 years in California we have been calling this out as a hazard. Believe me a professional inspector calls this out for replacement.

  • FPE circuit breakers have been an issue for many years for us at Kski electric We replace the entire panel when possible. some folks just do not understand the danger when circuits do not trip and some panels have no main breaker Sample 1949 issue panel 70amp panel rating for 50amp AC and four branch circuits, but kitchen was remodeled for 1200square foot Sherman oaks home all original breakers. think they will trip?? Have not yet?? Wow..
    thanks We will send this notice on, ?? home owners ins.. ?? fire coverage ??
    They were warned and do not care!!!!

  • Another issue with the FPE Stab Lok circuit breaker panels is loose breakers. These breakers have a small contact area with the bus strip and when the panel cover is not fastened down securely, the breakers can loosen up, causing the contact area to be even smaller. This causes the overheating noticed in the photos in the article.

    • During the first year of my apprenticeship (1973) I worked for a NECA contractor wiring new homes using FPE Stablock breaker panels and aluminun romex. It seems that whomever purchased these homes received a double whammy as far as their electrical systems were concerned.

  • As a homeowner, what type of company should I be searching for that can perform an electrical panel inspection? Most electrical contractors are not at an “engineering” level and simply connect things together. I suspect water intrusion in my box (C&H c. 2008) at some prior point and I have had one arc fault breaker fail, but it is difficult to determine if it was water or some other cause.

    • Hi Richard,

      This is a job that could be done successfully by an electrical contractor. You might need to explain that everything is working properly now, but you are concerned with corrosion or water contamination within the components. Most electricians like to come in and fix something that is broken and then make it work correctly after the repair. In this case, you may need to explain ahead of time, that you do not mind paying the hourly rate for a thorough inspection including looking for signs of corrosion or water intrusion. This may involve removing the actual breakers and inspection the breakers and the busbars behind the breakers.

      It is possible that the inspection will reveal that everything is normal inside. At this point, there will be a charge for the work performed and then you would have to be willing to pay for the work performed even though no actual repair was needed. If the inspection reveals that there is internal damage, then there will be an additional charge for the corrective measures needed.

      Another option, if you are highly concerned would be to just have the existing panel replaced. This would put all the cost toward a new panel rather than a possible charge for finding out it’s fine. You will need to address the source of the water if there is a water problem. It will do no good to have a new panel if the water keeps entering the panel.

      Water intrusion will need to be addressed either way. Some earlier arc-fault breakers were a bit fickle and would nuisance trip. Be careful about basing your action on the tripping alone. Do you see rust in the enclosure? Are there rust drip marks running down the wall behind the panel? Can you see corrosion or crusting on the exposed breakers parts?

  • Thanks John for this reminder on electrical safety. This prompts me to think more proactive steps to monitor the life of electrical parts (there are a LOT there in the machines I handle).

  • I purchase UBI Federal replacement breakers from a Breaker rebuilder. These are brand new, and every breaker sold is checked on their machine.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.