Under which condition is a portable generator not required to be connected to a grounding electrode conductor?

The condition where a portable generator is not required to be connected to a grounding electrode conductor is when it is equipped with a ground detector. This is because a ground detector is designed to monitor for any leakage current that could indicate a grounding issue. If a ground fault is detected, the ground fault protection device will activate to disconnect the power, preventing potential electric shock or equipment damage.

The use of a ground detector essentially mitigates the need for a dedicated grounding electrode because it provides real-time monitoring of the ground state, ensuring safety without relying on a traditional grounding method. This is particularly relevant for portable generators, which are often used in various applications and locations where standard grounding practices may be difficult to implement.

In contrast, when a generator is supplying only equipment that is mounted on it or when the equipment is cord-and-plug connected, there are different safety considerations that generally necessitate grounding to prevent any potential hazards. Additionally, non-current-carrying metal parts being connected to the generator frame does not eliminate the requirement for a grounding electrode in all scenarios, as grounding serves critical roles in safety and equipment protection depending on the setup.