M428 Generic 5A Cartridge Fuse 5 x 20mm, 5 Amp Universal Appliance and Electronics Part

M428 is a generic 5 amp fuse in the 5 x 20mm cartridge size, a miniature fuse format found in many appliances, chargers and pieces of electronic equipment. Use it wherever the old fuse is marked 5A and measures 5mm across by 20mm long. Match the blow characteristic too, as marked on the old fuse, with F for fast acting and T for time delay.

Why a 5A fuse blows and what to check

A fuse is a deliberate weak link. The thin wire inside melts when the current goes past its rating, cutting power before a fault can overheat wiring or damage the circuit board. A blown glass fuse often shows a broken or blackened wire, though ceramic bodied fuses have to be tested with a multimeter. If a new fuse blows straight away, the fuse is not the problem. Something downstream, such as a shorted motor, element, capacitor or board component, is drawing too much current and needs to be found before the appliance goes back into service.

Part details

• 5A current rating
• 5 x 20mm cartridge size
• Generic universal replacement fuse
• For equipment that specifies a 5A 5x20mm fuse

Replacing the fuse safely

Unplug the appliance or isolate the power first, and let any capacitors discharge before reaching inside. Remove the old fuse from its holder or clips and read the markings on its end cap. Never fit a higher amp rating than the one specified, as that removes the protection the fuse is there to give. If the new fuse blows, stop and have the fault diagnosed.

Questions about this part

Can I use a 10A fuse instead?

No. Always fit the same amp rating as the fuse you are replacing. A higher rated fuse lets more current through before it blows, so a fault could overheat wiring or components instead of being stopped.