Question
11. Undergrounded alternating-current system from 50V to 1,000V or less3 polints
that are not required to be grounded in accordance with 250.20(b) shall
have
ground detectors installed for ac systems operating at not less than 120V and at
1,000V or less
the ground detection sensing equipment connected as close as practicable to where
O
the system receives its supplies
ground detectors installed for ac systems operating at not less that 120V and at
O 1,000V or less and the ground detection sensing'equipment connected as close as
practicable to where the system receives its supply
O ground-fault protection for equipment
Answer
Ground detectors must be installed for AC systems operating at 120V or higher and up to 1,000V, and the ground detection sensing equipment must be connected as close as possible to the system's power source. Ground-fault protection for equipment must also be installed.