A 30-ampere, 120/240-volt circuit is protected by a 30-ampere fuse. What is the minimum size of the overcurrent protection device required for this circuit?
- A20-ampere fuse
- 30-ampere fuse
- C40-ampere fuse
- D50-ampere fuse
Exam tip
Always match the overcurrent protection device rating to the circuit rating.
Why B is correct
According to 240.4(A), the overcurrent protection device must be of the same rating as the circuit. Therefore, a 30-ampere fuse is the minimum size required for a 30-ampere circuit.