I am trying to replace a plug fuse in my electric panel. I have been using "P" type 20 amp fuses. Now all I can find is "TC" type 20 amp fuses. This new kind is referred to as a "Dual Element Fuse" and is apparently designed with a time delay. Am I correct in thinking that the "Type" ("P" vs "TC") doesn't matter, but the "Amps" are what matters? Am I safe to replace the Type P with the Type TC as long as it is the same amount of amps? Thanks very much!


The ampacity of the fuse is certainly the most important thing. Replacing a time delay fuse with one that does not have a delay can cause problems with motors starting up, and putting in a time delay into a dedicated electronic circuit can cause that circuit to fail catastrophically when the fuse does not blow in time.

In your case though, there should be no problem with putting in a time delay fuse. The TC fuses are specifically designed to provide superior protection for residential circuits.

Updated on January 11, 2018

Original Article:

How to Replace a Fuse in a Fuse Box
By Dan Harmon