After posting I did some more research on the FPE issue. I found a lot of dramatic stuff, as well as a very well organized treatise. I link to that below.
If I could sum up the issues, here's a "Stab" at it "LOL"
1) Panel design: FPE panels have some design issues that can lead to later problems. Aluminum instead of copper bus bars stood out. Copper is a better conductor, and probably stronger as well. Also the "Stab-Loc" attachment design, which is how the breakers connect with the buses, doesn't provide maximum material contact, just on the edges. Some panels have spring mounted bus bars, which don't provide a stable enough installation.
2) Breakers: FPE breakers appear to have some things backward. Whereas with other breakers is is sometimes advised to toggle the breakers periodically to keep them "limber" and better prepared to trip under overload or short conditions, FPE breakers react negatively to this exercising and it can increase their tendency to fail under overload or voltage surges.
3) Panel size. As with many older panels, FPE panels were designed to an earlier code. Later codes require more space inside the panels for wiring etc. This problem is with many older panels, but might be an additional reason to replace and FPE panel.
FPE itself was found to have falsified product testing for certification by a variety of underhanded methods. Why this did not result in a nationwide product recall is a subject for debate. Apparently budget constraints with the CPSC in the early 1980's as a given as a reason for not launching a recall research effort and ultimate recall requirement. And by that time FPE was out of business.
Now, as far as my house goes.... I don't make a habit of playing with the breakers, so they have limited mechanical insult, at least for the last 20 years. Also, like I said, I have observed various FPE breakers tripping under overload, including a 30 amp circuit that goes to the patio kitchen and adjacent fish pond area. In fact there's a vintage GE window/wall AC unit in there that will reliably trip the 30 amp FPE breaker inside the main house. So I don't use that AC unit. I have never detected a heat problem in either of the FPE panels (there's another one in the workshop). And as I said, when I bought the place, the inspector said he'd checked out the panel in the house, pulled some breakers, and didn't see any sign of heat/arcing/distortion damage. He was a pretty thorough guy, leaning towards giving the negative side on most things, so it did give me some piece of mind. If I had to do it again, I would have opted to dump some more cash into the house to replace the panels and the knob and tube in the month before I moved in. Woulda coulda shoulda.
All that said, I've decided that the FPE panels are on their way out. The question is when. When I moved in I noticed there are other issues, such as knob and tube wiring to half of the older parts of the house - the rest of the house and the addition are more modern - including rigid conduit, armored conduit, and NM cable. There are some things that were done very well, such as the large diameter rigid conduit running from the main service breakers to the house panel in the entry, and then more rigid conduit to the newer wiring and then on out to the workshop (underground, it's a separate building). So there is some good stuff here. The FPE panels, not so good.
So I have to decide how much work is necessary at this point. Minimally, the house panel has to be upgraded (I want more breakers in it anyway). It currently has a 2 pole 40 amp breaker running to the workshop. So even if I keep the FP panels (there are two, one for lighting, the other for outlets) in the workshop a while longer, upgrading the house panel will provide a new 40 amp dual pole breaker for that which while it might not address minor overloading that gets by the workshop panel, at least will trip in the face of massive electrical surges, which are the really scary ones.
After that, upgrade the service to the home from 100 amp 2 pole to 200 amp 2 pole.
Then, replace what remains of the knob and tube in half of the older part of the house with 3 wire grounded.
Finally, replace the FPE breaker panels in the workshop.
Along with all this I have an eye to putting in solar power on either the house roof or the workshop/garage roof. I don't want to do that, however, until the panel/wiring issues are addressed. However it might make sense to involve a solar contractor for advice as to the best combinations to accept later solar power infrastructure. Better than redoing everything and then finding it needs to be redone again to accommodate solar power generation.
When? Probably not until I retire which could be as early as next year. Might take a couple of years, though.
One though I had along the way here... on this issue... over the past decade or two I've been conserving electricity, with more efficient appliances (two fridges), as well as replacing incandescent lighting, first with CFL's and then to LED's. This means less load on the breaker panels and probably reduces a little the chances of a failure.
Anyway, thanks for bringing this up. I still think the current (no pun intended) situation is safe, but it could be safer and it will need to be addressed.
