[Eric]

How do you decipher the value of fuses. Soe of them in my gear have letters like D or F followed by a number then the letter A. Do the letters D and F have values?

[Wayner]

As an example a fuse labeled ABC-10 250VAC, the ABC is a fuse style, the 10 is the amperage rating of the fuse and 250VAC is the voltage rating. All fuses also have a designated fail type like "slo-blo".

The real message here is to always replace the blown fuse with the same type and rating. If the fuse blows quickly again, it's time to see the doctor.

Wayner 

[Eric]

How do you tell if it is a fast-blo vs slo-blo

[Wayner]

Usually slow blow will say on the fuse cartridge. Look on the metal cap. If it doesn't say slow blow, it isn't.

Wayner

[Eric]

The reason I am asking is I am looking to go to some high perfromance fuses. The 5x 20's are hard to read.

[*Scotty*]

Owner's manual?
Scotty

[Wayner]

There is no such thing as a "high performance fuse" IMO. Ask the guy you got them from. You can also ask him if they are UL listed.

Wayner

[Wayner]

I'm so sick of claims by snake oil makers about high performance shit, just like this. Perhaps you should have loaded your quandary at the beginning.

W