HOLT Electricians Practice Exam

For general motor applications, the motor branch circuit short-circuit ground-fault protection device must be sized based on which reference?

1. Manufacturer's specifications

2. NEC Table

3. Local codes

4. Industry standards

The correct answer is: NEC Table

Sizing the motor branch circuit short-circuit ground-fault protection device according to the NEC (National Electrical Code) Table is crucial because it provides standardized guidelines that are essential for ensuring safety and compliance with national electrical standards. The NEC outlines specific requirements for the sizing of protection devices, which helps prevent equipment damage and enhances the overall safety of electrical installations. Using the NEC Table ensures that you are following the established regulations that take into account various factors, including motor size, type, and operation. These tables provide the necessary values that help in determining the correct rating for circuit breakers or fuses, which is fundamental in protecting motor circuits from overloads and faults. While manufacturer's specifications can provide important information specific to a particular motor, they must still conform to the general guidelines established by the NEC to maintain safety standards. Local codes may also add additional requirements beyond those in the NEC, and industry standards provide broader guidelines, but typically align with NEC directives for specific scenarios. Therefore, the NEC Table serves as the authoritative reference for this particular requirement.