Federal Pacific Electric FPE Stab-Lok® DIY Testing?
FPE DIY TEST ADVICE - CONTENTS: Federal Pacific Electric Stab-Lok® Circuit Breaker field testing recommendations: can you and should you test FPE Stablok panels or breakers in place in a building? No. Here are the reasons. Does a visual inspection of an FPE panel assure its safety? No. Why not?
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
DIY FPE Breaker Tests: FPE Federal Pacific Electric Stab-Lok® Electrical Panel & Circuit Breaker testing in the field: is it a good idea to test the FPE circuit breakers installed in an FPE Stab-Lok Panel right in the building? Are FPE breakers that "pass" an in-situ test then considered safe? Or does testing actually increase the risk of a future failure? What about a do-it-yourself Stab-Lok circuit breaker test to see if the breakers will trip properly? Page top photograph courtesy of Raleigh NC home inspector Steve Smallman.
Replacement FPE Stab-Lok® circuit breakers are unlikely to reduce the failure risk of this equipment. We recommend that 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.
Guide to Do-it-yourself DIY Federal Pacific Electric Stab-Lok® Circuit Breaker Testing? Really?
The bottom line: testing FPE Stab-Lok circuit breakers in place is not recommended
"Testing" FPE circuit breakers by applying a load may give an instantaneous picture of the performance of individual breakers but it does not predict their performance when a real safety problem occurs (overcurrent) later.
More important, except if performed by a very expert person, in-place testing is very dangerous, risking fires in the building being tested.
And particularly with this circuit breaker, applying an overload to it actually increases the chances that the breaker will fail to trip later on a subsequent, perhaps real-world unsafe condition.
In addition to the explanation offered here of why testing an FPE Stab-Lok electrical panel or circuit breaker in-place by using a meter on the circuit or by applying an overcurrent on the circuit is unsafe and does not assure product safety, we list below additional reasons to avoid fooling yourself about in-situ testing of FPE Stab-Lok breakers.
There are other hazards in FPE electrical panels besides the breakers, including bus and bus insulation meltdowns and shorts.
"Exercising" the FPE Stab-Lok circuit breakers by turning them on and off has not been shown to "un-stick" or in any other manner improve the probability of working properly, and conversely, such activity may in fact increase the chances of a future failure
Replacing what you think are "bad" circuit breakers with newly-obtained ones may not lessen the risk.
Even if you could replace all the FPE Stab-Lok® equipment with (somehow magically obtained) all "new" FPE Stab-Lok® equipment (found in a used-or new-old-stock warehouse for example) the risk level for the building would not be sufficiently different from before the replacement and would remain high: there remains a latent risk of fire from failure of these breakers to trip in response to overcurrent.
Similarly, the risk level if you replaced these breakers with after-market replacement units there is little evidence that the performance of the equipment would be improved (though testing remains inadequate on that product set.)
What about a visual inspection of the FPE Panel to Check its Safety: no electrical tests, just looking
FIGURE 8 - FPE Stab-Lok® ® "RULE-OF-SIX" (SPLIT-BUS) PANEL WITH NO MAIN BREAKER. THE JUMPER CABLES ON THE RIGHT SIDE
FEED THE LOWER SECTION.
On first glance, the FPE
Stab-Lok® ® panel previously shown in Figure 8 looks normal. In fact, however, it clearly demonstrates several
of the hazardous failure modes discussed in the previous sections. It is one of
17 collected for the recent testing. It is from a home built in 1974, whose new owners had determined in 1999 that it
should be replaced.
Their decision to replace it was in part prompted by information available on the internet regarding
FPE breaker problems.7 According to the homeowner, who sent it to me
for examination and testing, "We recently had it replaced and found the breaker to the dryer fried in just the
way described. Our electrician was astonished. Two others we had bids from dismissed our concerns with contempt."8
Viewing the panel from the front, some signs of overheating, as
previously discussed (p. 7) are evident. These are subtle compared to the view looking down at the top right (dryer)
breaker, as in Figure 9.
Reader Question: couldn't I individually test (overload) each FPE circuit to be sure the breaker trips?
2/22/2014 erick said:
I have this panel in my 1980 modular home. Couldn't I individually test (overload) each circuit to be sure breaker would trip? Under controlled situation this seems safer and preferable to waiting for an event.
Reply: About a do-it-yourself test of an FPE panel in a home: Four Good Reasons to Stay Away from In-Home FPE Tests
No do not try testing circuits in your home. Doing so, even if you were a trained electrician or electrical engineer involves several very serious errors and misconceptions.
First: serious risk of building fire: testing an electrical circuit in-situ risks overloading the circuit and starting a fire in the building. When a circuit breaker is overloaded, say by plugging in an excessive load at a receptacle on a receptacle circuit, you may not know how quickly the breaker should respond by opening the circuit, you may not know where in the circuit a particular point of high resistance means that remote or hidden overheating may occur, and you may start a fire or injur someone, perhaps at a surprise location.
When I assisted (mostly observed would be an appropriate term) Jess Aronstein in such testing electrical outlets for a different project investigating wire connector overheating in a home, he, an experienced and trained professional electrical engineer,. PhD and researcher, instrumented ever single connection and devices on the circuit, monitored all of them for temperature rise, and used additional safety measures that are beyond the scope, training, and equipment of normal people. And very detailed, tedious, and costly.
Second: increases the risk of a subsequent no-trip failure: even worse: testing an FPE breaker by overloading it very significantly increases the chance that on a subsequent, real-world overload case that occurs in the building the breaker will not trip - resulting in a fire, injury or loss at that later time.
There are several reasons for this, just one of which is the jamming that occurs in a 2-pole breaker when overloaded on one leg. No problem may be apparent at that time, yet on a future overload, there is roughly a 60% chance that the FPE Stab-Lok CIRCUIT BREAKER thus PREVIOUSLY OVERLOADED WILL NOT TRIP under ANY LOAD!
Even switching these breakers on and off (exercising the breaker) can increase the chances of a future failure to trip.
Thus an FPE breaker that was "tested" and appeared to respond properly is at greater risk of a future failure to trip than if it had not been tested at all.
Third: other known hazards are not tested: And there are other hazards in the FPE electrical panel including bus design issues, arcing, bus failures and inability of the bus to retain some breakers, as well as a very serious hazard that occurs when a breaker toggle is moved to the "OFF" position but in fact the breaker remains "ON" internally.
Fourth: invalid test methodology: the type of over-current test that one might imagine an electrician or DIY FPE Test person in their home, presumably someone with some expertise in electrical codes, design, and engineering, would without special equipment be invalid in that it is unlikely your test would come close to the (already weak) UL 486 standard for circuit breaker testing.
UL486, described in general terms, requires that the circuit breaker be exposed to a range of overcurrents through and past the rated circuit breaker ampacity combined with a monitoring of the timed response of the breaker to trip or open the circuit. A circuit breaker must open at different speeds (faster) for higher current draw than at lower current draw (longer response time) - perhaps to reduce nuisance tripping that would occur at a brief current surge that might be harmless.
Notwithstanding the limitations of the current UL-486 tandard (testing can be done by the manufacturer, in private, and breakers tested may not come from the open market), it seems to me that a do-it-yourself test that simply chose an arbitrary overcurrent and applied it onto the circuit not only risks a house fire or causing a future circuit breaker failure it also does not comply with the standard, which means the test says little or nothing about the circuit breaker's actual performance.
More reasons to avoid do it yourself electical circuit overload and circuit breaker testing in the home include the discussin below, and I imagine some readers can post comments suggesting still other reasons that this is a bad idea - like maybe your insurance company would have objections?
The illustration AT LEFT, excerpted from FPE Stab-Lok® TECHNICAL REPORT illustrates an example of FPE electrical panel failure (bus burn and melt, loss of insulating material) that is not visible when the breakers are plugged-into the panel.
(This view is of the backside of the panel. The damage could
not be seen unless the panel is taken out of the enclosure.) [Click for larger picture]
FIGURE 3 - OVERHEATING AT THE CONTACT BETWEEN THE BUSSBAR AND THE
STAB SOCKET ASSEMBLY CAUSED THIS DAMAGE TO THE INSULATION.
So sorry, I too would be thrilled if there were a cheap easy fix for this hazard.
The only effective repair is to replace the FPE Stab-Lok electrical panel entirely, or to use Eaton Cutler Hammer's entire panel bus assembly replacement. That allows you to keep the panel enclosure - the steel box, while installing a completely new bus assembly and new CH circuit breakers.
Reader Question: A local electrician advertises for FPE Replacement but I've never had a problem with my panel - I will just have an electrical contractor test it for me instead
I received an advertisement from a local electrician offering to replace this panel in my Williamsburg home. Sounds like a scam. This house is 31 years old and no problem with my Federal Pacific panel. If I want to have my panel checked I would choose an electric contractor with good ratings on Angie's List and not respond to some ad dropped at my door. - Jimmy Jo 4/12/12
Reply: Really? testing an FPE Stab-Lok panel in place, even by a licensed electrician, does not assure its safety and may make it less safe than before
On the one hand, it makes perfect sense to hire an electrician who is familiar with FPE Stab-Lok® electrical panel hazards. After all, the risk of hiring an electrician to replace an FPE Stab-Lok® but who is unaware of the hazards involved means you might be hiring someone who is generally not well informed - which means there may be a risk of other mistakes or poor work.
On the other hand, if an electrician is getting business by scaring people inappropriately, s/he may not be someone you want in your home.
On the third hand, an electrician who warns you that FPE Stab-Lok® electrical panels are unsafe is not saying anything incorrect nor inappropriate. The hazards are well documented, and we agree that the panel should be replaced.
Recommendation Against In-Home Testing of FPE Stab-Lok® electrical panels, breakers, circuits
Watch out: in any case, "testing" or "inspecting" an FPE Stab-Lok® panel on-site by an electrician is a fundamentally bad idea.
Not only will tests not be conclusive unless performed by one of very few experts, using special equipment and under very carefully monitored conditions so as to avoid setting the house on fire) but worse, "tests" of FPE Stab-Lok® circuit breakers by switching them on and off, or by applying an overcurrent, is at risk of significantly increasing the risk of a future failure - after testing OK the breaker may be at much greater risk of not tripping in response to an overcurrent should one occur, or simply not turning "OFF" internally even when you switch the toggle to the "OFF" position.
Those are very serious hazards made worse by the DIY FPE test process in the first place.
For an example of actual testing of FPE Stab-Lok equipment see FPE HAZARD REPORT - 2017 [PDF] independent research article by Jess Aronstein, supercedes older FPE hazard reports by this author - and you'll have a better idea of how this work is performed on a test bench.
Testing FPE Stab-Lok electrical panels or circuit breakers in-situ in a building or performing circuit overload testing in-situ in a building for any electrical panel is a risky idea, more so for equipment in which the breakers may not trip (set the house on fire) or for equipment like the FPE line in which testing itself may increase the risk that the breaker won't trip later in response to an actual overcurrent or other unsafe condition.
In sum, there is no need for FPE testing in your home, we already know that the equipment is hazardous, and such tests are unreliable and dangerous and increase the risk of a future failure.
All I have to say to Jimmy Jo is "Good luck!" You may need it. How do you know the panel is "fine"? Do you know if any of the breakers have ever been called upon to trip? I am a home inspector, and have seen numerous Stab Lok panels, some looking just as clean and pretty as when they were first installed. What does that mean? ABSOLUTELY NOTHING!! Those panels have been there all that time, and have likely never been overloaded.
Maybe yours have functioned properly, as I'm sure others have, but with the failure rate reported by well-respected electricians and other professionals, I would not want to risk my life or property for $1500. Why do we purchase insurance? For financial protection, even though you may never need it. Think of replacing an FPE panel in the same way. An insurance policy against loss of your house or life. Speaking of that, many insurance companies WILL NOT ISSUE A POLICY if they know an FPE panel is present. - Joe 8/4/12
thanks for the comment, we agree completely. Just because you never noticed a problem with a no-trip circuit breaker that's no promise that everything's fine. My jeep's seat belt is cut to a single thread. Each time I drive to the rifle range in my Jeep I fasten my seat belt. So far, I've never been in a car crash, so it's obvious that the seat belt is working "just fine" - right? - Editor.
Continue reading at FPE FAILURE FIELD REPORTS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Ask a Question or Search InspectApedia
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Note: as we didn't add this reviewers list until 2007, this list of technical reviewers is incomplete; we have received comments and suggestions
regarding this topic, edits and remarks included, from engineers and management from the US CPSC, electricians (many listed at our
page on field reports of FPE failures), home inspectors, licensed electricians, and electrical engineers, and even a few attorneys and
real estate agents, since 1986. Technical review, critique, content suggestions, questions, or clarifications are invited and
where a contributor wishes, credit and links will be provided to that source. Contact us to provide feedback.
 Dr. Jess Aronstein, electrical engineer, Poughkeepsie, NY, forensic engineering services, independent laboratory testing for various agencies firstname.lastname@example.org (independent electrical panel testing, including FPE Stab-Lok® panels, to April 2010)
 David Carrier, electrical engineer, 53 Henmond Blvd., Poughkeepsie, NY 12603 845-430-7527 email@example.com (independent electrical panel testing, including FPE Stab-Lok® panels, beginning 2010)
 Alan Carson, Carson Dunlop Associates, Toronto, Ontario. Mr. Carson is a home inspection professional, educator, researcher, writer, and a principal of Carson Dunlop Associates, a Toronto home inspection and education firm. Mr. Carson is a past president of ASHI, the American Society of Home Inspectors
 Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator.
 Carl Grasso, Esq., Herzfeld & Rubin, New York, NY. Mr. Grasso is an attorney who managed a plaintiff's class action litigation against Federal Pacific Electric in New Jersey.
 William King, US CPSC Director of Electrical Engineering (Retired).
 Licensed Electricians: FPE FAILURE FIRE PHOTOS includes electricians who have provided cases and photographs of field failures of FPE equipment at this website.
 Homeowners, Home Inspectors, Electricians: FPE FAILURE FIELD REPORTS includes anecdotal field reports provided by a range of contributors including electricians (and some home owners or home inspectors) who have provided cases and photographs of field failures of FPE equipment at this website.
 "Experts say electrical panels in Dallas-area homes may be a fire waiting to happen", Christina Rosales, The Dallas Morning News, August 21, 2010,
firstname.lastname@example.org continues to attend to the unresolved issues around FPE Stab-Lok® equipment and the lack of a clear US CPSC Warning.
 FPE Stab-Lok® Panel Failure Research, Public documents on FPE obtained under FOIA: The following reports on defects (non trip and burning) of FPE Stab-Lock Circuit Breakers 8 were obtained from Consumer Product Safety Commission by request, under the Freedom of Information Act:
"Status Report - Evaluation of Residential Molded Case Circuit Breakers", Wright-Malta Corp., (For U.S. Consumer product Safety Commission, Project# CPSC-C-81-1455), August 10, 1982 (Contains analysis of mechanism of failure of FPE two-pole Stab-Lock breakers.)
"Failure Analysis of Residential Circuit Breaker Panel", Wright-Malta Corp., (For U.S. Consumer product Safety Commission, Project #CPSC-C-81-1455), May 20, 1982 (Contains failure analysis of FPE Stab-Lock panel that ignited due to failure of buss-bar interconnections in the backside of the panel.)
"Phase II Report, Evaluation of Residential Molded Case Circuit Breakers", Wright-Malta Corp., (For U.S. Consumer product Safety Commission, Project# CPSC-C-81-1455), March 10, 1984 (Contains experimental analysis of materials, construction, and performance of molded case circuit breakers, including FPE. Lack of corrosion resistance of certain internal parts is considered to be a factor in the failure of the circuit breakers.) More about the galvanic scale and corrosion between dissimilar metals is at GALVANIC SCALE & METAL CORROSION.
"Final Report: Calibration and Condition Tests of Molded Case Circuit Breakers," Wright-Malta Corp., (For U.S. Consumer product Safety Commission, Project #CPSC-C-81-1429), December 30, 1982 (Extensive calibration and functional testing of FPE breakers. Substantial percent failures to trip on overload.
 2011 FPE Stab-Lok® ® Hazard Study published in 2012
Jesse Aronstein, Ph.D., P.E., and Richard Lowry, Ph.D., "Estimating Fire Losses Associated with FPE Stab-Lok® ® Circuit Breaker Malfunction", IEEE ESW-2011-29, Industry Applications, IEEE Transactions on, Jan.-Feb. 2012, reviewed and accepted for publication and presentation at the IEEE Electrical Safety Workshop, Toronto, January 28, 2011. Retrieved 10/2/2012, original source - IEEE link: http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6074935 &url=http%3A%2F%2Fieeexplore.ieee.org%2 Fxpls%2Fabs_all.jsp%3Farnumber%3D6074935
Abstract - A method is presented for connecting small branch
circuit breaker functional test data to statistical fire loss data.
Test results are presented for field samples of a particular line
of circuit breakers that have an abnormally high defect level.
The test results are then utilized in combination with available
electrical fire statistics to estimate the annual number of fires
and consequent injuries, deaths, and monetary loss associated
with the defective breakers. An estimate is then made of the
reduction of injury and loss that can be achieved by
encouraging replacement of the defective breakers. The role of
the electrical safety community in promoting
replacement of the
defective breakers is discussed.
 2011 Commission Closes Investigation Of FPE Circuit Breakers And Provides Safety Information For Consumers, Revised 18 Feb 2011.
2008 - 2007 FPE Stab-Lok® TECHNICAL REPORT (revised) - an updated test report of independent testing (a large 1.2MB PDF file) using a larger pool of FPE Stab-Lok® circuit breakers than the older CPSC and Wright Malta tests found significantly higher failure rates of FPE Stab-Lok® circuit breakers, including a look at critical safety failures (breaker failed to trip at 200% of rated current or jammed) which found up to 80% failure rate for FPE Stab-Lok® GFCI circuit breakers (n=4), 12% failure rate for double pole FPE Stab-Lok® circuit breakers (n=120), and a 1% failure rate for FPE Stab-Lok® single pole circuit breakers (n=345).
2008 FPE Class Action Lawsuit Results: In May 2008 the FPE Class Action Lawsuit in New Jersey was finally settled. New Jersey homeowners who were the original owners of an FPE Stab-Lok® electrical panel received $500. in settlement as part of the action. Institutional class members also got varying amounts, depending on their installations.
No one received the full cost of panel replacement. New Jersey Judge's Summary Judgment for the Plaintiffs against FPE 8-15-2002 & 29 October 2002 - "FPE violated the Consumer Fraud Act because FPE knowingly and purposefully distributed
circuit breakers which were not tested to meet UL Standards as indicated on their label and there is an ascertainable loss for which treble damages
are recoverable;" as reported by the Superior Court of New Jersey.
2007 FPE Stab-Lok® TECHNICAL REPORT - an updated test report of independent testing (a large 1.2MB PDF file) using a larger pool of FPE Stab-Lok® circuit breakers than the older CPSC and Wright Malta tests found significantly higher failure rates of FPE Stab-Lok® circuit breakers, including a look at critical safety failures (breaker failed to trip at 200% of rated current or jammed) which found up to 80% failure rate for FPE Stab-Lok® GFCI circuit breakers (n=4), 12% failure rate for double pole FPE Stab-Lok® circuit breakers (n=120), and a 1% failure rate for FPE Stab-Lok® single pole circuit breakers (n=345).
Steve Smallman, Raleigh, NC, Email: email@example.com, Website: http://stevesmallman.com/ - Quoting: Steve Smallman Property Inspections (SSPI) inspectors have performed or supervised over 25,000 inspections since we introduced home inspections to the Triangle area in 1980. Mr. Smallman is a contributor to InspectApedia.com and has commented on or provided information on plumbing traps, commercial FPE electrical panels and DIY Tests of FPE equipment,, roofing underlayment, and building exteriors.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: firstname.lastname@example.org. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones