NEC Commercial Electrical Practice Test

The ampacity of feeder conductors supplying more than two-wire branch circuits must be a minimum of how many amps?

1. 30 amps

2. 40 amps

3. 50 amps

4. To be determined by load

The correct answer is: To be determined by load

The ampacity of feeder conductors supplying more than two-wire branch circuits is determined by the actual load the feeders will carry. This approach ensures that the conductors can handle the maximum anticipated load without overheating or becoming unsafe. The National Electrical Code (NEC) provides guidelines that consider the specific applications, including factors such as load diversity, demand factors, and continuous loads that may vary. Determining the necessary ampacity based on these factors allows electricians and engineers to size the conductors appropriately to prevent failure and ensure safety and efficiency in the electrical distribution system. By not specifying a fixed minimum number of amps, the code reflects the need for a more customized solution based on the unique circumstances of the electrical installation. This promotes a safer and more effective electrical system that can adapt to the actual usage patterns of the circuits involved.