A Summary of the Problem: Federal Pacific Stab-Lok Electric Panel and Circuit Breaker Hazards

Having reviewed documentation regarding this issue, and having discussed the issue with forensic experts in the field, I am convinced that a latent hazard exists where FPE Stab-Lok circuit breakers continue in use. The hazard is worst for double-pole breakers. Published reports of actual tests that were performed indicate that under certain conditions it is possible for one leg of these circuits to attempt to trip the breaker, resulting in a jammed breaker which will afterward not trip under any load condition. A reader might infer from the CPSC 1983 press release that the manufacturer and some Commission members were of the opinion that these conditions would not occur in the field.

This is an erroneous conclusion. Some very common household appliances operate are powered by a two-pole 240V circuit (protected by the type of breaker under discussion) but use two or more independent 120V sub-circuits inside the appliance. Two obvious cases are electric clothes dryers and ranges. If, for example, the low-heat (110V) heater in a dryer were to short to the dryer case, a serious overcurrent would occur on one "leg" of the circuit.

Another wiring practice, using a single two-pole breaker to power a split circuit which uses a shared neutral, such as may be installed in kitchens in some areas, is nearly certain to have each leg of the circuit loaded independently and thus subject to single-leg overloading and subsequent breaker jamming. A breaker which jams and then fails to trip under this condition is, in my opinion, a serious fire hazard.

A more careful reading of the CPSC press release of March 3, 1984 suggests that the authors were careful NOT to conclude that there is no hazard, but simply that the information at hand did not prove the hazard, and that the Commission did not have funds to pursue testing. In this document, the representation that no real hazard exists is made by the manufacturer of the device - not exactly a neutral party, and even that wording is cautious in tone: "FPE breakers will trip reliably at most overload levels." Readers should see the failure rates cited in the IAEI letter below.

FPE Stab-Lok Equipment Means Latent Fire Hazards

It's the exceptions that cause fires. An FPE circuit breaker will appear to "work just fine" in passing along current to the circuit it feeds, until there is an overcurrent, short circuit, or similar condition. When those exceptional conditions occur, this equipment fails to protect the circuit and the building from overheating and fires, in some cases at a failure rate around 60% of the time. I estimate that the normal industry failure rate on circuit breakers is less than .01%.

Consumers should read and follow the Commission's advice regarding circuit breakers. But this advice is insufficient. The Commission's admonition to avoid overloading circuits and to turn off and have examined devices which seem to be creating a problem is a poor substitute for reliable, automatic, overcurrent protection. It is precisely because dangerous conditions can and do occur without adequate recognition and action by a consumer that circuit breakers and fuses are installed to provide overcurrent protection in the first place.

Therefore it is hardly an adequate "fix" for FPE breakers to just tell consumers to handle these cases manually.

It is possible that some breakers may perform with adequate reliability, possibly those manufactured after the companies discovered safety defects and improper practices in listing the product, and possibly those manufactured in Canada. However, in absence of an explicit statement from the manufacturer and/or the US CPSC indicating that newer stock equipment is defect free, and considering that defects occur in both breakers and the panels themselves, and finally, that testing showed failures in both in-use equipment and new off-the-shelf devices, my advice to consumers and electricians is that these panels be replaced with newer equipment, particularly those which use 240-volt double-pole breakers described in the literature. In my opinion, if a fire or other hazard occurs with this device, neither the manufacturer nor the Commission, who have suggested in the press release that data was inconclusive or inadequate to establish a hazard, will accept responsibility for losses that may ensue.

This article is reprinted from an industry publication. I would be a hippocrit if I did not admit that I have two Federal Pacific panels in my home and do not plan to replace them. Bob Walstead