How far above the earth should aluminum conductors be terminated when used outside as a GEC?

The correct height for terminating aluminum conductors used outdoors as a Grounding Electrode Conductor (GEC) is 18 inches above the earth's surface. This requirement is established to ensure safety and to minimize the risk of physical damage to the conductors. Terminating at this height allows for adequate clearance from the ground, helping to protect the conductors from environmental wear, moisture, and potential grounding issues that could arise from immediate contact with soil or water.

By adhering to this designated height, electricians ensure compliance with industry standards, which aim to maintain the integrity and reliability of electrical systems throughout their lifespan. The specific measurement of 18 inches strikes a balance between accessibility for maintenance purposes and protection from hazards.