There are several panels that a home or business owner should be aware of, that may pose a possible hazard to his or her home or business. I have list the following panels along with information and links that will assist the home or business owner in making an educated decision if he or she is in doubt as to whether he or she will need to upgrade and or replace their electrical panel.
a). Federal Pacific Equipment Panel (FPE): Federal Pacific Breakers may not trip as required when an overload is present in an electrical circuit. There have been studies and test done on these breakers and according to the reports, the breakers fail more than they work and for that reason, most insurance companies will not write fire for homes or commercial building unless the FPE Panel are replaced. Here are some links that should clear up any questions that you may have about the hazards of FPE panels.
http://inspectapedia.com/fpe/FPE_Stab_Lok_Identification.php
http://inspectapedia.com/fpe/FPE_CPSC_Investigation.php
http://inspectapedia.com/fpe/FPE-Hazards-Revised-070525.pdf
b). Zinsco Panels: Zinsco breakers design flaw is different from FPE design flaw because the Zinsco breaker connection to the bus bar can become loose due to the breaker losing its tensile strength either due to heat and or age, then the connection begins to arc, then heats up and cools down, resulting in excessive expansion and contraction of the connection between the breaker and the bus bar, causing it to arc and heat up even more, creating a snowball effect and possibly starting a fire. The problem with Zinsco Panel is that you cannot see if the breaker has become loose and is arching even with the panel cover off. To verify if the breakers are arching on the bus bar, an electrician must remove and inspect each breaker and the bus bar where the breaker is attached. Here are some links that should clear up any questions that you may have about the hazards of FPE panels.
Below is a Zinsco panel:
