What must the voltage rating of a fuse be compared to the supplied voltage?

The requirement for the voltage rating of a fuse to be greater than or equal to the supplied voltage is crucial for safety reasons. Fuses are designed to protect electrical circuits by breaking the circuit if the current exceeds a certain level, which can be a sign of an overload or short circuit. For the fuse to operate effectively and safely, it must be capable of handling the maximum voltage that may be present in the circuit.

If a fuse has a voltage rating lower than the supplied voltage, there is a risk that it could fail to adequately interrupt the circuit when necessary. In such cases, the fuse may not withstand the electrical pressure, leading to catastrophic failures, equipment damage, or even fires. Selecting a fuse with a voltage rating equal to or exceeding the maximum voltage ensures that it can safely interrupt current flow without risk of electrical arcing or additional hazards.

This is why the correct approach is to select a fuse whose voltage rating is always greater than or equal to the supplied voltage, ensuring that it functions properly under normal and fault conditions.