coolvt: "With the talk about these "won't trip".....were these things UL listed, and if so, how did they ever past muster?" I've heard the stories about the FPE panels before, but never really understood what it was about. This thread inspired me to do some Google research. The results have been very interesting... In several hours of reading, it appears that the best-documented failure mode of the FPE panels is this: Some of the double-pole breakers, when presented with a fault on only one pole, will jam internally when they try to trip. The jam prevents the breaker from tripping, and once it occurs, the breaker will not trip under any circumstances. One test found that around half of the double-pole breakers they tested exhibited this failure mode. It only happens to double-pole types (and maybe to types with 3 or more poles, although I haven't found anyone who has tested same). It's also possible that a jammed breaker will remain closed on one or both poles even after the handle is moved to the "OFF" position. There doesn't appear to be any easy way to tell a good breaker apart from a bad one, other than subjecting it to an overcurrent (definitely not recommended for the DIY'er). Another failure that is pretty well documented is that the bus bars and connectors on the breakers (they are push-in types) do not hold good contact over time. The connectors on the breakers lose tension; the contacts heat up, and the rather thin bus bars can melt or burn. Also, it appears that the bars themselves can shift and cause breakers to come loose. Apparently there are a lot of breakers that are only being held in by the panel cover. There are a number of anecdotal reports of single-pole breakers that failed to trip under significant overload. However, unlike the case with the double-pole breakers, I haven't found any testing that has uncovered a mechanism by which this can occur. Oddly, in most of the reports I've found on the single-pole breakers, the culprits were 20A ones. There is also mention in a few places that the panels did not offer enough space for wire routing, and that some practitioners bent incoming large-gauge feed wires excessively in order to make them reach the terminals, resulting in failures later when the over-stressed wires pulled loose. One site mentions that the panels did not meet the 1981 NEC spec for wire bending room, which is possible since the design predates 1981 by quite a few years (going back to the '60s apparently). As for the question of the UL cert: about a year after Reliance Electric bought out FPE in 1980, they issued a press release acknowledging that FPE had engaged in fraudulent practices in obtaining at least some of their UL listings. There are different reports in exactly how this was done; at least two ex-FPE insiders claim that FPE had a rigged test setup for their UL-witnessed tests. Reliance ceased manufacture of FPE panels in 1981, but there was quite a bit of product in the distribution pipeline at the time which was not recalled. Also, a company in Canada which had rights to the design continued to manufacture them until some time in the 1990s.

Here is a link. FPE breakers and panels are both subject to more than the average number of problems. The breakers are legendary for the amount of overload they will endure and not trip, if in fact the breaker will trip at all. Many of these breakers just burn up when overloaded. The Stab-Loc buss allows breakers to be inserted incorrectly and for the contact on the breaker to be easily bent. I've removed many panels where a poor contact between the breaker and buss have been a near-fire experience. Further, although new breakers can be had for the panel, you will find the cost 4 or 5 may often exceed the price of a new panel - plus. GFCI and AFCI breakers aren't available, or haven't been. And, after replacing the branch circuit breakers there's still the matter of having a main braker thet is 30+ years old. A replacement for these generally isn't available, or isn't available new, and certainly isn't a common stock item - A real blessing if it fails during a cold snap, holidays, relatives visiting, etc., etc. For what it's worth, the company that owns Square D (NOT GE!) bought the remains of FPE and still manufactures the junk in Canada, and indeed have had a recall up there for breakers that wouldn't trip. The same company manufactures the breakers sold here for whoever currently holds the license for the name use and design. I used to keep breakers from old FPE panels to use when I ran into people who needed work done on FPE equipment and just absolutely didn't have the money to get it replaced. Nowdays I smash all removed breakers with a hammer. Let's just say I donate a bit back to the community every year and folks with FPE issues and money trouble might benefit from some of this. Anyway, I won't work on/in FPE panels any more. I just see too much liability. Rant over: Just do yourself a favor and get the panel updated with something that is currently manufactured and will have parts available at most big box and neighborhood hardware stores.

"I have just one Federal Pacific stab loc panel in my 90+ year old home. One would assume it works fine, the upstairs trips if a space heater is used with a couple of lights, right? " Every time it trips degrades the equipment and increase the chance of NOT opening on an overload the next time one occurs. Very old FP does not appear to have as much of an issue as the newer stuff. Quality simply went down hill until the fires started showing up. Everything from simply not opening on overload to not opening all poles of multi-pole breakers has been seen. At least if the fire is away form the panel the defective equipment can be found once the fire is out (as opposed to being so damaged in a fire that it is very difficult to perform an 'autopsy.'

This site is probably the most informative one I've found about FPE hazards. I personally have had mixed experiences with FPE. I grew up in a 24-unit apartment complex that was all FPE. In my 16 years there, I have memory of an electric baseboard heater, an electric water heater, and two electric ranges that shorted/otherwise_failed_and/or_emitted_a_lot_of_smoke and never tripped breakers. Also, one breaker that was manually flipped OFF did not actually open the circuit, as the plumber changing the water heater discovered when he tried to cut the wires, blew a hole in his wirecutters, and tripped the main breaker (GE), blacking out the entire apartment. All of the breakers I have seen malfunction were double-pole. Given my own experience, I personally would replace the box if at all possible.