Federal Pacific Electric Stab Lok Panels in a gang Other FPE Panel Defects
Additional Reasons to Replace Federal Pacific Electric FPE Stab Lok electrical panels

  • OTHER FPE DEFECTS - CONTENTS: Bus design and breaker-bus connection design problems provide additional reasons to replace FPE Stab-Lok® and Federal NOARC electrical panels besides failure-to-trip
  • POST a QUESTION or READ FAQs about other FPE Stab-Lok® equipment hazards that have been identified in addition to the failure-to-trip problem.
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This article describes additional hazards and potential defects in Federal Pacific Electric / Federal Noark / and some Federal Pioneer electrical panels besides the problem of circuit breakers that fail to trip. These conditions add force to the argument for complete replacement of the equipment.

Replacement FPE Stab-Lok® circuit breakers are unlikely to reduce the failure risk of this equipment. We recommend that residential FPE Stab-Lok® electrical panels be replaced entirely or the entire panel bus assembly be replaced, regardless of FPE model number or FPE year of manufacture. We do not sell circuit breakers nor any other products. For more information see FPE REPLACEMENT PANELS and FPE REPLACEMENT BREAKERS. This page assists in identifying Federal Pacific Electric Stab-Lok® electrical panels and circuit breakers. More FPE information is in the links listed at the "More Reading" links at the bottom of this article .

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It is information for building inspectors, home buyers, home owners, electricians exploring the background of possible hazards associated with Federal Pacific Electric Stab-Lok® circuit breakers and service panels.

OTHER DEFECTS - Federal Pacific Electric Equipment issues extend beyond basic design of the Stab Lok Circuit Breaker

FPE Stab-Lok Circuit Breaker Panels, studies, performance, specifications were not stable

But it's more complicated than that. The company actually changed the design from time to time (without necessarily telling anyone). On the other hand, No one has provided any technical or even anecdotal data suggesting that any of these changes corrected basic design flaws. In addition, there was the problem of equipment UL-listing label swapping and therefore mislabeling individual pieces of equipment, therefore incorrectly stating the use to which individual pieces of equipment could be applied.

FPE-Design and possibly original equipment used to produce Stab-Lok Circuit Breakers sold under other brands

FPE USA stopped making equipment quite a while ago, but Stab-Lok® (TM) panels and circuit breakers continued to be produced in Canada, under the name Federal Pioneer, a Canadian "FPE" company which was later bought by Schneider Electric, also in Canada.

Federal Pioneer Stab-Lok® circuit breakers and panels continue to be available even still as new today. Some of my Canadian contacts claim that the Canadian product was better than the U.S.-made version but my own first-hand view of some of it in the home of a Canadian Home inspector was that it was just as bad. (The circuit breakers had to be held into the panel using adhesive tape!)

Several years ago I called Schneider Electric and was able to speak with a Schneider engineer about this product. I asked if they had changed the design to fix any of the inherent problems with the product series over the U.S. version. I was promised an answer to this question - the engineer was quite polite. But in follow-up calls no one at the company wanted to provide any information about this product.

If a manufacturer cannot, or will not provide their supporting test or other data for a product professionals are forced to err on the safe side by refusing to endorse it.

"Trust me" just doesn't cut it where electrical safety is concerned.

FPE Stab-Lok Circuit Breaker Panels had Other Design Issues Besides the Main Defect: circuit breakers that do not trip reliably

Doughlas Hansen, an ASHI home inspector, educator, and building failures researcher produced an inventory of FPE Stab-Lok electrical panel problems besides the principal and most-serious defect of circuit breakers that could not be relied upon to trip off in the event of an over-current. Again in 2012, Douglas, writing with Redwood Kardon, an electrical expert from CodeCheck updated that original FPE defect inventory.

Hansen organized his critique of FPE Stab-Lok equipment into three categories:

  1. Old equipment, manufactured to "less stringent codes and standards than modern equipment". Under this heading Hansen cites
    1. Over-crowding in the electrical panel (not unique to FPE) and he includes additonal crowding that results of some design features specific to FPE such as failiure to meet code-specified wiring clearances and inadequate space for wire bending. Hansen cites both gutter space and wire bending space defects in FPE panels.
    2. Spring-loaded (adjustable) bus bars no longer permitted by current electrical codes; indeed we have reported elsewhere of a fatality that occured when an electrician opened the front of a spring-loaded bus designed electrical panel.
    3. Confusion about the "on" position of circuit breaker switches: in some FPE panel models "down" is "on" for some switches.
    4. Split bus panel design features of some FPE panels are critiqued by Hansen
    5. Accidental breaker tripping: Hansen also notes that it is difficult to remove the panel cover without accidentally tripping some circuit breakers (this is not a feature unique to FPE)
  2. Problems unique to the design of the FPE Stab-Lok circuit breakers - not found in other electrical equipment of the same age. Among these I [DF] would include Hansen's critique of the method of connection of the circuit breaker to the power bus in the electrical panel.

    1. The name "Stab-Lok" is a hint that the breakers are not connecte3d using a clip that binds the breaker to the bus bar but rather a "stabbing blade" that makes the electrical connection. Indeed in the home of another building expert (A.C., Toronto) I observed FPE Stab-Lok breakers that were so loose in their mounting position that they were being held in the panel by cellophane adhesive tape!

    2. Hansen notes that it's common to find scorch marks on the breaker-to-bus connecting parts, but I pose that this may not just be due to a poor connection it may also be due to overcurrents on breakers that were not tripping when they should, combined with arcing at the loose connector.
    3. Doug also points out that because FPE panels included two different connecting bus designs, an "E-shaped" opening and an "F-shaped" opening, it is too easy to try to plug the wrong circuit breaker onto a mis-matched bus, resulting in a damaged, bent and unsafe electrical connection.

      Really? I'd include a warning not to try pushing an E-breaker into an F-bus (and vice versa) except that you should be replacing the entire electrical panel, not individual FPE Stab-Lok breakers.

  3. Manufacturing defects and circuit breaker failures. Aronstein, press releases, and many sources have noted that in 1982 when Reliance Electric was in the process of obtaining FPE it was disclosed that FPE product listings had been obtained by deceptive means, that the company's products lost their UL listing, and that deceptive practices in testing and labeling had continued over many years. Actually the problem was noted and discussed in the press as early as 1980.
    See EXXON Buys a Scandal 1980

Mr. Hansen cites the third defect as the most serious one. A review of research by Jess Aronstein suggests that categories #1 and #2 can be folded together: the failure of FPE Stab-Lok circuit breakers to trip when they should was and remains a combination of circuit breaker design and manufacturing tolerances that permitted the moving parts of the circuit breaker to jam internally.

See FPE HAZARD REPORT - 2017 [PDF] independent research article by Jess Aronstein, supercedes older FPE hazard reports by this author. for the most-complete technical research and testing of these products.

Not only do the circuit breakers fail to trip reliably when they should in response to an overcurrent, the initial response of the breaker to an overcurrent can cause an internal jam-up of its moving parts such that on an subsequent over-current the breaker may fail to trip under even the most extreme over-current loading. And an overcurrent on one leg of a 2-pole breaker causes internal jamming that prevents the breaker from tripping in the future.

  1. Replace the FPE electrical panel, not individual circuit breakers. We have heard from many readers about using replacement FPE circuit breakers in panels where there have already been failures as well as where owners want to add circuits.

    Listing by UL or other agencies for FPE Stab-Lok circuit breakers can be confusing. For example Federal Pioneer circuit breakers that are made to the FPE Stab-Lok design may not be listed for U.S. use.

    Watch out: there is no data supporting the claim that replacement FPE circuit breakers perform better than the original equipment and both field reports and testing suggest that opposite: repalcement FPE breakers do not perform better than the originals and in some cases may in fact be "original" or OEM breakers or breakers made on the same equipment using the same procedures and made to the same standards and specifications as the originals. This appears to be the case for FPE Stab-Lok "replacement" circuit breakers made in Canada, China, and Mexico and sold under several brands including "American".

    Watch out: replacing the circuit breaker will also fail to address any of the bus design, burned/damaged bus, panel crowding, or other defects described by Hansen or others. You should replace the FPE Stab-Lok breaker panel entirely rather than replacing individual circuit breakers.


Continue reading at FPE REPLACEMENT PANEL or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


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