New York State Master Electrician Practice Exam

What is the minimum ampacity requirement for feeder conductor compared to service-entrance conductors?

1. 30 Amps or less

2. 40 Amps or less

3. 50 Amps or less

4. No minimum requirement

The correct answer is: 50 Amps or less

The minimum ampacity requirement for feeder conductors in relation to service-entrance conductors is a critical concept for electrical systems. In general, feeder conductors must be sized to handle the load they are expected to serve safely and efficiently. The National Electrical Code (NEC) outlines that feeder conductors typically need to have a minimum ampacity that matches or exceeds the ampacity of the service conductors they derive from. In this case, the correct choice indicates that feeder conductors must have a minimum capacity of 50 Amps or less. This is aligned with NEC standards, which establish that feeders should be capable of handling the maximum load from the service-entrance conductors without risk of overheating or failure. The rationale behind setting such a requirement is to ensure safe and reliable operation of electrical systems. If the feeder conductors are not appropriately sized, there may be risks of overloading, which can lead to electrical fires or system malfunctions. Therefore, ensuring that feeder conductors have an ampacity that meets this minimum threshold directly contributes to the safety and functionality of the entire electrical installation.