Fuse Ratings Explained
Fuse Ratings Explained
A fuse’s ampere number is only one part of its specification. The datasheet and equipment manual tell you whether it can carry normal current and safely clear a fault in the actual circuit.
A 10 A fuse may carry 10 A under specified ambient conditions, but it does not necessarily open at 10.1 A. The exact curve and temperature matter. A marking such as T2A 250V typically indicates a time-delay 2 A cartridge with a 250 V rating, but do not infer an AC/DC rating or interrupt capacity absent from the full part data.
To replace a fuse, match the equipment’s specified current, characteristic, physical form and required interrupt capacity; verify that its voltage rating covers the circuit for AC or DC as appropriate. For a new circuit, also protect the wire and check source fault current.