Electrical Service Panels
Posted: 7 years ago
Electric service panels can be considered the "Heart" of the electrical distribution system in the average house. For the most part, I see mostly modern service panels that do a good job of protecting homes from fire caused by 1) overcurrent- this is what happens when an electrical malfunction on a branch circuit causes excessive amperage on a circuit. Excessive amperage creates heat in the wires and then you get fire. 2)electrical arcing which causes sparks which then cause fire.
There are a couple types and brands of service panels that have known problems.
Federal Pacific. May also be seen as Stab Lok, or Bulldog. Federal pacific was named in a class action lawsuit because the breakers for these panels were knowingly manufactured despite not being compliance to Underwriters Laboratories (UL) standards.
What happens is an electrical event may happen that requires a breaker to trip, stopping power delivery to that circuit thus avoiding a fire. Federal Pacific breakers fail to reliably stop power, increasing the chances of fire in homes with this equipment.
Federal Pacific was granted patent protection for their Stab Lok breakers in the early 1950's, and shipping of this equipment stopped in 1980. You can still get these breakers at many hardware and suppliers.
There is no known "repair", and a visual examination cannot determine a good breaker from a bad one. FPE panels may function reliably for years without issue. Unfortunately the only way to know a breaker will fail is for there to be excessive current on a FPE protected circuit and the breaker fails to trip. For peace of mind that your family is protected, these should be replaced.
Sylvania/Zinsco
The story with Sylvania or Zinsco panels is much the same as with Federal Pacific. With Sylvania, though the breakers are known to fail and then become welded to the bus bar due to excessive current and heat. Once this happens they no longer protect as they should.
Other thoughts
Split bus panels
These were manufactured by a lot of companies, and used a group( up to 6) of breakers to feed power to another section of the panel, as there is not one "main" power disconnect or breaker.
In and of themselves, these do not have the latent problems unless they are one of the trouble makers listed above. However, if you have a split bus service panel it is very likely 40 or more years olf and beyond its expected service life.
Fuse Box
A fuse box is just old equipment. They are very easy to ask too much of, electrically speaking. They commonly are only capable of properly supporting a handful of circuits. Because of the electrical demand of modern life, it is very common to find them modified inappropriately. Add to that their ability to be unsafely modified( pennies used instead of fuses, or the wrong fuse size) and they should be upgraded to modern equipment.
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