Home Repair

30 Amp Glass fuses

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Looking at a Fuse panel, I see 6 fuses some blue marked 15, some red marked 20 and some green marked 30
Why would they make a 30 when it requires a #10 wire and getting a #10 wire into that panel would be almost impossible.
Secondly , two of the fuses are marked as Type S and the thread size
is a smaller diameter than the thread size of the other fuses, which are sized more like that of a standard light bulb. I realize that some fuses blow fast and some are designed with a slight delay, but why are there two different socket sizes of a different diameter, in a fuse box of only 6 circuits.
Hi Peter,
Okay, some panels are not designed so well for larger wire. Not much we can do about that.
The Type S fuse has a smaller base "rejection" type because it is designed for only one size of fuse. In other words, tamperproof. The base of this fuse actually screws into the standard size "Edison" base.
It is a time delay fuse. Used on older homes for furnaces, pumps etc.
You can replace this with a "T" type fuse which will give you the time delay and is a standard edison size socket. If it is working well, just leave it. If it is blowing, then check the load to find out the problem. Never install a different fuse until you know all the facts!
In most cases, I would recommend upgrading to a breaker panel for the homeowner.
Hope that helps!
Thanks for the advice, Rob. Nice to have you aboard!


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