Electrician's Licensing Practice Exam

Which NEC Table covers grounding electrode conductor sizing?

1. NEC Table 250.100

2. NEC Table 250.66

3. NEC Table 250.130

4. NEC Table 300.5

The correct answer is: NEC Table 250.66

The correct answer pertains to NEC Table 250.66, which specifically addresses the sizing of grounding electrode conductors. This table provides guidelines for determining the appropriate size of grounding electrode conductors based on the size of the largest ungrounded conductor feeding the service or the largest conductor in the system. Proper sizing is crucial for ensuring the effectiveness of the grounding system and for providing adequate protection against electrical faults. Understanding this is vital for electricians because improper sizing can lead to safety hazards, such as inadequate grounding during fault conditions. The other tables mentioned do not focus specifically on grounding electrode conductor sizing; rather, they cover different aspects of grounding and installations. For instance, NEC Table 250.100 relates to grounding electrode systems, while Table 250.130 pertains to the grounding of separately derived systems. NEC Table 300.5 addresses the burial depths of conductors, which is not relevant to grounding electrode conductor sizing.