InspectAPedia ^®

We recommend that residential FPE Stab-Lok electrical panels be replaced entirely or the entire panel bus assembly be replaced entirely, regardless of model number or year of manufacture. We recommend against replacing individual FPE Stab-lok circuit breakers. We do not sell circuit breakers nor any other products.

Here we illustrate the real hazards of multi wire branch circuits and single pole circuit breakers where FPE Stab-lok equipment is installed. We define "latent safety hazard." This document explains the latent electric shock and fire hazards associated with Federal Pacific Electric Stab-Lok electric panels and circuit breakers. Federal Pacific Electric "Stab-Lok" service panels and breakers are dangerous and can fail, leading to electrical fires. The problem is that some 240-Volt FPE circuit breakers and possibly also some 120-Volt units simply may not work. Readers of this document should also see FPE FIRES: Failure Reports and The Federal Pacific Stab-Lok Electric Panel Hazard Website. © 2009 Daniel Friedman, All Rights Reserved.

No part of this article may be reproduced electronically or at websites - use is reserved to the author. Printed copies of this material may be made and distributed provided that it is not sold nor used to sell or endorse other products, and provided the original source website is prominently displayed.

FPE Stab-lok Hazards - Multiwire Branch Circuits

Special Notice: Multiwire Branch Circuits - warning: to avoid overheating neutral wire and shock hazards involving multiwire branch circuits, it is important to assure that each of the individual circuits is on opposite poles (in the panel) from the other.

In most panels this is accomplished, in fact forced, by using a 240-V common-trip-tie breaker (ganged together switches) which forces individual circuits onto opposite poles. However in FPE panels, the panel bus design does not provide this assurance. -- Rex Cauldwell

See Multiwire Branch Electrical Circuits and Split-Wired Receptacles - Electrical Wiring Safety Requirements - Note this is background on multi-wire circuits and is not FPE specific except that since I recommend wiring these circuits with double pole breakers and double pole FPE breakers don't trip very well, it's an important concept.

FPE Stab-lok Hazards - Single Pole Breakers

It is possible that there are similar failures among single-pole (120V) breakers. At least one case of a single-pole 120-Volt FPE GFCI breaker which failed to trip has been reported.3 Furthermore, simply purchasing new circuit breakers of the same type from the same manufacturer may not correct the problem. And only special FPE breakers fit in the FPE "Stab-Lok" electric panel.

When this issue was examined in the early 1980's, FPE's opinion was that the chances of an overload occurring on only a single pole of a 240-volt breaker were very small. In our view there are some very common real-world examples where single-pole loading in a 240-volt breaker might include failures: multi-wire branch circuits and in electric clothes dryers where one of the heating elements shorts to the steel case of the dryer.

FPE Stab-lok Hazards - Latent Safety Hazard Defined

The circuit breakers do not directly cause an electrical fire. Some other failure must occur which in turn causes an overload of the circuit "protected" by the FPE breaker. When the breaker fails to trip in response to the overload it has failed to provide the protection intended, and a fire may result. That indirection is why we call this a "latent safety defect."

Why we call this a "latent safety defect" rather than just "hazardous" or "dangerous" needs more explanation. Unfortunately, some people who stand to face big costs grasp at fine distinctions about the failure mechanism in order to avoid facing the problem.

When a defect is itself likely to cause injury directly, such as live wires poking out of the wall by the bathroom sink, we call it a "hazard."

When a defect does not directly cause the injury or loss, such as a circuit breaker which may fail to trip when something else is causing an unsafe overcurrent, we call it a "latent safety defect.

Either way, it's still a problem that needs prompt attention.

FPE Stab-lok Hazards - Case Reports of Failures

Is this a linguistic debate or is it really an issue in the field? You bet it's an issue. Recently during an examination by a Maryland home inspector (citations 4,5 below) an FPE panel, was observed and flagged as a potential hazard which should be remedied. The property owner, concerned about his sale, complained and threatened to sue the inspector. This was not an isolated case.

We were able to provide the inspectors with referral to Dr. Jess Aronstein, an engineer in Poughkeepsie, New York, who in turn provided supporting documentation: reports on this problem, a bibliography, and a press release from FPE.

In another example of the dangers of this "latent safety defect," Dr. Aronstein reported that during a disturbance in a jail, a guard hit a gang-switch in an FPE "Stab-Lok" load center in the cell block area. The breaker did not trip. Rather, it shorted to ground in the switch, blowing a hole in the cover plate. (Citations 6,7)

Building inspectors and renovators often face the discovery of a product which is potentially harmful, which should be replaced, but for which there is little public documentation to justify their position.

Disagreement among people affected by this issue means that it's necessary to be able to cite actual research and actual real-world fire and failure reports.

• Continuing to collect and provide FPE Stab-Lok field reports, we invite readers, building owners, inspectors, and electricians, to report their experience with this equipment - see REPORT YOUR FAILURE
• At REPORTS OF FPE FAILURES we have collected a large number of field reports of failures, fires, overheating, case explosions, and simple failure trip for this equipment.
• A master list of FPE Studies is at FPE Stab-Lok HAZARDS & REPAIRS WEBSITE-Reports-List

Share this Article      

...

Technical Reviewers & References

Search InspectAPedia

• Daniel Friedman - principal author/editor of the InspectAPedia^® Website
• InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
• Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
• Additional technical contributors & reference sources for this article are listed below.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

FPE Stab-Lok HAZARDS & REPAIRS WEBSITE
SUMMARY OF the FPE Stab-Lok PROBLEM
FPE HAZARD ARTICLES, STUDIES
FPE Stab-Lok TECHNICAL REPORT
HOW TO IDENTIFY FPE & FP
REPORTS OF FPE FAILURES
HOW TO REPORT FPE INCIDENTS
FPE REPAIR ELECTRICIANS
FPE REPLACEMENT BREAKERS
FPE REPLACEMENT PANELS
FPE REPLACEMENT PANEL COSTS
CAN'T AFFORD A NEW ELECTRIC PANEL?
FEDERAL PIONEER in CANADA
FIRES WAITING TO HAPPEN
  How Many Stab-Loks
  Stab-Lok Failure Rate
  Proper Repair
  Proving the Hazard
  Multiwire Circuits
  Single Pole Breakers
  Latent Safety Hazard
  Failure Reports
  Technical Reports
FPE HISTORY
ADVICE TO HOME BUYERS w/ FPE PANELS
HOME INSPECTION LANGUAGE for FPE Stab-Lok
IAEI LETTER

More Reading:
Federal Pacific Electric (FPE) Panel Fire and Failure Photos
Federal Pacific Electric (FPE) Panel Fires and other Failures: Anecdotal Field Reports

• Dan Friedman is a building consultant in Poughkeepsie, NY. He served as chairman of both the Education Committee and the national Technical Committee of the American Society of Home Inspectors. For Content Suggestions, Contact information is at his website. Because of website traffic volume, if you are seeking contact to ask a technical question, please handle it by email, not telephone.
• Rex Cauldwell: "Safe Wiring Practice," Rex Cauldwell, Journal of Light Construction, letter March 1995, p.6.
• 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
• 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 (Ret).
• Licensed Electricians: FPE Fire and Failure Reports includes electricians who have provided cases and photographs of field failures of FPE equipment at this website.
• Homeowners, Home Inspectors, Electricians: Federal Pacific Electric (FPE) Panel Fires and other Failures 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.

More Information on Building Diagnostic Inspections and Repairs

• The Federal Pacific Stab-Lok Electric Panel Hazard Website Safety Information for Consumers. 1983
• Home Inspection Reporting Language and discussion for FPE panels
• How to Identify FPE Federal Pacific Stab-Lok Electric Panels - is yours one of these? ALSO: A History of the FPE Stab-Lok Issue.
• FPE FIRES: Failures continue: FPE breaker fails, results in fires: field reports
• Federal Pacific Electric Fires Waiting to Happen, Debate Waiting to Be Ended, detailed article
• Replacement Circuit Breakers for FPE Stab-Lok Electric Panels? are not recommended. We recommend replacement of the entire electrical panel, or replacement of the entire electrical panel bus assembly. See FPE REPLACEMENT PANELS for details.
• Replacement Panels for FPE Stab-Lok load centers - options include conventional complete panel replacement and a less costly replacement of the panel interior load center/bus assembly
• * Safety Hazards and Safe Inspection Procedures for Electrical and Home Inspectors at Residential Electric Panels
• Aluminum Wiring Information Website Aluminum Electrical Wiring Hazards and Repairs: in-depth authoritative info, photos, documents including selection of proper vs. ineffective repair methods. E.g.: Ideal 65 "Twister" purple connector fails in field and lab testing with aluminum wire.
• Ampacity of an Electrical Service: How to determine the electrical service size or ampacity entering a building
• Circuit Breaker, a bad one fails to trip failure at aluminum bus-to-circuit breaker connection - field report and photographs
• Electrical System & Wiring Hazard Inspection, Detection, Cause, Remedy, Prevention - Main Electrical Page
• Electrical Panels, How to Inspect in Buildings, safety for electrical inspectors, electrical panel, fusing, wiring defects, defective products. Inspection Class Presentation
• Lightning Strike Risk Assessment, Protection Systems & Services
• Multi-wire branch circuit inspection and defects


• Directory of Home Inspectors accessible via internet


• Carson Dunlop's Home Inspector's Home Study Course (DJF is a contributor and participant in this education project).

InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.

The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

< Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

Building Inspection, Problem Diagnosis, Forensic Investigation & Testing, Repair Consulting

Contact Daniel Friedman for website content suggestions or for fee-paid consulting

Search InspectAPedia