Need to know proper ampere valu for fuse.

Herman...YES, fuses are labeled. However I find that while the voltage rating (of little importance) is usually readable, the important current rating often is not. Why do they do this?

ALL fuses are timed devices. The amount of current they will carry (without blowing) depends on how long the current flows. A common type of fuse will blow in about one second if the current is twice the rating. It can carry even higher current for less time. It will carry its rated current for ever.

A slo-blow fuse will carry current greater than its rating for a longer time. Slo-blow fuses are used where brief current surges well above the steady state current are expected. Typically this is for electric motors, which suck amps at startup, and for electronics power supplies which draw high current until capacitors are charged up.

No thin-wire type fuse is fast enough to protect a transistor from a dead short, although it might avoid secondary failures. There are "Fuses" that can protect transistors, but these are actually transistors themselves (not wire) and they cost as much as or more than the transistors they protect. So they are only used where the protected transistors are difficult or impossible to replace.