Under what circumstances should phase conductors be grounded during the electrically safe work procedure?

Under what circumstances should phase conductors be grounded during the electrically safe work procedure?

• A. Ground the phase conductors in cases of induced voltages or stored energy
• B. Keep the circuit energized
• C. Use only a warning sign
• D. Disconnect all grounds

Answer: (A)

Ground phase conductors must be grounded whenever there is a possibility of induced voltages or stored energy. Even after a circuit is opened, nearby energized equipment can induce voltages in conductors, and stored energy in capacitors or inductive elements can keep a voltage present. Providing a grounding path ties the conductor to earth, allowing any residual energy to dissipate quickly and bringing the conductor to the same potential as the surroundings. This minimizes the risk of shock or arc flash to workers during maintenance. Keeping the circuit energized leaves the hazard in place; relying on a warning sign does not remove the energy; disconnecting all grounds removes the protective reference and can leave equipment floating and dangerous.

Ground phase conductors must be grounded whenever there is a possibility of induced voltages or stored energy. Even after a circuit is opened, nearby energized equipment can induce voltages in conductors, and stored energy in capacitors or inductive elements can keep a voltage present. Providing a grounding path ties the conductor to earth, allowing any residual energy to dissipate quickly and bringing the conductor to the same potential as the surroundings. This minimizes the risk of shock or arc flash to workers during maintenance. Keeping the circuit energized leaves the hazard in place; relying on a warning sign does not remove the energy; disconnecting all grounds removes the protective reference and can leave equipment floating and dangerous.