How many fuses are required to protect a 120-volt, 1-phase, 2-wire branch circuit in a 600-volt fused safety switch?

In a 120-volt, single-phase, 2-wire branch circuit, protection is typically achieved through the use of a single fuse. This is because the circuit consists of two wires: one hot (live) and one neutral. The fuse is installed in the hot wire to protect the circuit from overcurrent conditions.

Using one fuse effectively interrupts the circuit when exceeding the designated current capacity, thus safeguarding the equipment and wiring from potential damage due to overload or short circuits.

In a 600-volt fused safety switch, this switch provides the capability of a higher voltage but does not require additional fuses for a low-voltage branch circuit operating at 120 volts. Extra fuses would not provide added protection for such a setup, as the inherent circuit design only necessitates one fuse to disconnect the supply when a fault occurs.

Overall, the requirement here aligns with standard practices in electrical design for circuits of this nature, confirming that one fuse is adequate for protection in this scenario.