ICC Residential Electrical Inspectors Practice Exam

What is the minimum size copper grounding electrode conductor required for a service conductor of 600 kcmil aluminum?

1. 2

2. 3/0

3. 1/0

4. #4

The correct answer is: 1/0

To determine the minimum size copper grounding electrode conductor required for a service with 600 kcmil aluminum conductors, one must refer to the National Electrical Code (NEC) guidelines, specifically those outlined in Article 250, which deals with grounding and bonding. For conductors, the NEC provides tables that specify the sizing of grounding electrode conductors based on the size and material of the service conductors. In this scenario, a 600 kcmil aluminum service conductor falls under certain requirements for grounding. According to NEC Table 250.66, when considering the minimum size for a copper grounding electrode conductor, one would see that for an aluminum service conductor of 600 kcmil, the appropriate corresponding size for the copper grounding electrode conductor is 1/0 AWG. This is because the table outlines specific sizes based on the type of main conductor (aluminum or copper) and their respective kcmil sizes. This relationship is governed by the principle that grounding conductors are sized to ensure proper electrical safety and fault current handling capabilities, so it is essential to adhere to these specified sizes to maintain system reliability and protection. Thus, the minimum size copper grounding electrode conductor for a service conductor of 600 kcmil aluminum is indeed 1