Grounding is the most effective way of protecting electrical workers from electric shock. That is why it is important to ensure that all deenergized lines and equipment are grounded. (See Sections 4.5.2, 7.5.3, Figure 7-2,29 CFR 1910.269(n),1926.954, and IEEE 1048-1990, "IEEE Guide for Protective Grounding for Power Lines.")

7.5.1 PURPOSE

This section provides information concerning protection for workers repairing, servicing, or working on high-voltage power lines. (See 29 CFR 1910.269(n), 1926.954, and ASTM F-855.)

Figure 7-2. Equipotential grounding is the most effective way of protecting employees who are working on high-voltage systems and equipment.

7.5.1.1 REDUCE THE POTENTIAL VOLTAGE DIFFERENCES ACROSS THE WORKER

The primary function of personal protective grounds is to provide maximum safety for personnel while they are working on deenergized lines or equipment. This will be accomplished by making provisions that will reduce the potential voltage differences at the work site (voltage differences across the worker) to a safe value in the event that line or equipment being worked on is accidentally reenergized, voltages induced from other energized lines, an energized line falls on the line being worked, or there is a lightning strike near the line being worked.

The personal protective grounds should provide a low-impedance path to ground to ensure prompt operation of the circuit protective devices. For more information, see Section 4.15.2 and IEEE 80.