According to Table 250.66, an aluminum grounding electrode conductor can be used with what type of service-entrance conductors?

The correct choice indicates that an aluminum grounding electrode conductor can be used with either aluminum or copper service-entrance conductors. This is based on the provisions outlined in the National Electrical Code (NEC), specifically Table 250.66, which provides guidelines for the sizing of grounding electrode conductors.

In practice, this means that if the service-entrance conductors are made of aluminum or copper, an aluminum grounding electrode conductor complies with the NEC requirements. This flexibility is crucial for electricians, as it allows them to use aluminum grounding conductors without being restricted to a specific type of service-entrance conductor. It also allows for compatibility in various applications, providing greater options during installation and maintenance. The utilization of either conductor type enhances reliability and safety in electrical systems while adhering to regulatory standards.

This choice reflects an understanding of proper grounding methods and material compatibility, essential knowledge for electrical contractors working to ensure compliance with electrical codes.