Which NEC table is used for sizing grounding electrode conductors?

The National Electrical Code (NEC) provides guidance on grounding and bonding through specific tables designed for various applications. The correct table for sizing grounding electrode conductors is Table 250.166. This table outlines the minimum size of grounding electrode conductors based on the size of the largest ungrounded conductor or the equivalent area for parallel conductors.

Understanding the relevance of this table is essential for ensuring that grounding systems are effective and safe. Grounding electrode conductors are critical for providing a path to ground in electrical systems, helping to protect both people and equipment from faults or surges.

The other tables listed serve different functions: while Table 250.68 pertains to grounding connections, Table 310.16 addresses the ampacity of conductors, and Table 250.74 deals with the grounding of different types of structures. Each of these tables plays a role in the broader framework of electrical safety and regulation but specifically sizing grounding electrode conductors is addressed in Table 250.166.