Isolated ground receptacles must be identified by what marking?

Isolated ground receptacles must be identified by an orange triangle on the face of the receptacle. This specific marking is part of the National Electrical Code (NEC) requirements, designed to indicate that the receptacle has an isolated ground. The use of an orange triangle helps ensure that electricians and users can easily identify these special receptacles, which are intended to reduce electrical noise and improve the performance of sensitive electronic equipment.

This identification is crucial in environments where a clean and noise-free ground is needed, such as in data centers or laboratories. By marking these receptacles in a standardized way, safety and proper functionality can be maintained, as users are alerted to the special grounding requirements of the receptacle.