Master Electrician Practice Exam

According to the NEC, overcurrent protection of transformers rated at 600 volts or less must be sized in accordance with?

1. Table 450.3(A)

2. Table 450.3(B)

3. Table 450.5

4. Table 450.2

The correct answer is: Table 450.3(B)

The sizing of overcurrent protection for transformers rated at 600 volts or less is determined by Table 450.3(B) of the National Electrical Code (NEC). This table provides the appropriate overcurrent protection requirements specifically for transformers based on their rating and the type of transformer. Table 450.3(B) outlines the maximum size of overcurrent protection devices permitted for a variety of transformer types, ensuring that these devices can safely interrupt the load current without damage to the transformer or the connected circuit. It is essential for maintaining safety and preventing potential damages due to overloads. By utilizing the guidance provided in Table 450.3(B), electricians can effectively size overcurrent protection devices to help prevent issues such as overheating and fire risks associated with transformers. Understanding and applying these NEC guidelines is critical for proper installation and compliance with safety regulations in electrical work.