1 Packet of 4 x 3Amp BS1362 BUB Fuses - A fuse interrupts excessive current so that further damage by overheating or fire is prevented. Wiring regulations often define a maximum fuse current rating for particular circuits. Overcurrent protection devices are essential in electrical systems to limit threats to human life and property damage. Fuses are selected to allow passage of normal current and of excessive current only for short periods. If an excessive current is forced through the circuit will be broken and stop any current from passing.