5x20mm Glass Fuse 1A 250V Fast Blow – M205 Quick Blow Cartridge Fuse

Wiring & getting started

1. Check the size and rating

   Measure the old fuse: 20mm long and 5mm across is this size. Replace like with like: the same current, the same speed (F for fast, T for slow) and a voltage rating at least as high as the circuit.

2. Size it for a new circuit

   Pick a fuse above the circuit’s normal current, so this 1A fuse suits loads up to about 0.75A. If it blows every time you switch on a motor or transformer, the circuit needs a 1A slow-blow fuse rather than a bigger fast one.

3. Fit it in a holder

   Use a 5x20mm fuse holder in the positive or active line, as close to the power source as you can. Turn the power off before changing a fuse.

4. Checking a blown fuse

   A blown fuse has a broken wire or a darkened, smoky glass. A dark glass means a hard short, so find the fault before you fit a new one.