What is the minimum size GEC permitted from the service equipment to a 1/0 AWG bare copper ground ring?

The minimum size of the Grounding Electrode Conductor (GEC) from the service equipment to a 1/0 AWG bare copper ground ring is indeed 1/0 AWG. Grounding requirements are established to ensure safety and effectiveness in electrical systems. When connecting to a ground electrode system, such as a ground ring, the size of the GEC is based on the size of the grounding electrodes used.

Each type of grounding electrode has specific requirements for the minimum conductor size that can be used with it. In this case, a 1/0 AWG bare copper ground ring is employed as the electrode, and the National Electrical Code (NEC) permits a GEC that is equal in size when connecting to a grounding electrode that is the same size. Hence, using a 1/0 AWG GEC is acceptable to maintain continuity and effective grounding.

This rule is designed to ensure that the conductor has adequate capacity to handle any fault currents, thereby providing a path to ground with minimal impedance while remaining compliant with electrical safety standards. The approach is intended to protect electrical systems and personnel from hazards associated with electrical faults.