Electric Power Generation, Transmission, and Distribution eTool
An equipotential zone is a work zone in which the worker is protected from electric shock from differences in electric potential between objects in the work area. These differences in potential can be caused by induced voltage, line reenergization, or lightning. The worker in an equipotential zone is protected from electric shock because there is a near identical state of electrical potential between any two points on the body. To ensure that personal protective grounds will protect the worker from hazardous step- and touch-potential conditions, it is essential to employ recognized good engineering grounding methods, such as those in the IEEE Guide for Protective Grounding of Power Lines, IEEE 1048-2003. Those methods comply with the performance-oriented equipotential zone requirements contained in 1910.269(n)(3).
Power lines and equipment are considered energized and must be worked as live (with rare exception) if deenergized lines are not properly grounded.