HOLT Electricians Practice Exam

To determine the size of a motor branch circuit, what should one refer to?

1. Voltage rating table

2. Table 430-52

3. Electrical load calculations

4. Manufacturer's specifications

The correct answer is: Table 430-52

When determining the size of a motor branch circuit, Table 430-52 of the National Electrical Code (NEC) provides essential information. This table specifies the maximum permissible conductor sizes based on the motor's full-load current rating. It is critical for ensuring that the circuit can handle the expected electrical load while providing the necessary protection against overheating and potential fire hazards. Utilizing Table 430-52 allows electricians to select the appropriate conductor sizes needed for both supply and overload protection conditions specific to different motor types. It effectively correlates the current ratings of motors to suitable conductor sizes, making it a primary reference for compliance with safety standards. While other resources such as manufacturer's specifications may provide specific requirements per individual motors, and voltage rating tables may help with understanding system voltage, Table 430-52 specifically addresses branch circuit sizing for motors, making it the most appropriate choice for this task. Additionally, electrical load calculations, though important for other aspects of electrical design, do not directly provide the necessary sizing specifics for motor branch circuits as Table 430-52 does.