When a separately derived system is located outside a building, is a grounding electrode connection required at the outdoor source location?

In the context of a separately derived system located outside a building, a grounding electrode connection is not required at the outdoor source location if the system is not interconnected to any building or structure. This situation typically refers to systems like generators or wind turbines, which might not need direct grounding connections if they are designed to handle transient voltages and operate independently. The emphasis here lies on safety and the operational characteristics of such systems, which are often grounded through the electrical system they feed, rather than requiring a separate connection in every outdoor application.

This rule is consistent with the National Electrical Code (NEC) guidelines, which dictate that a removable source, like an outdoor generator, can have different grounding requirements depending on its configuration and use. Without a direct ground reference to a building structure, the necessity for a grounding electrode at the outdoor source diminishes, especially if the system has safeguards built in for operational safety and continuity.