【Daily Topic】【Electrical Edition 20160924】
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Participation reward: 2 Wealth. Reward for correct answer: 9 wealth. Which of the following statements is correct? ( ) A. For Class II lightning protection buildings (to prevent direct lightning strikes), the minimum allowable value of the grounding impulse resistance is 10Ω. B. It is strictly prohibited to use gas pipes as protective conductors. C. The grounding grid of 35 kV substations should be connected underground to the grounding electrodes of the incoming lightning protection wires; the length of the connection wires should be no less than 30 m. D. The PEN conductor in TN-C and TN-C-S systems must be insulated according to the highest voltage it may be exposed to. Correct answers: BD
B. It is strictly prohibited to use gas pipes as protective conductors
B. It is strictly prohibited to use gas pipes as protective conductors. D. The PEN conductor in TN-C and TN-C-S systems must be insulated according to the highest voltage it may be exposed to
The correct statements are (BD). A. For Class II lightning protection buildings (to protect against direct lightning strikes), the minimum allowable value for the grounding impulse resistance is 10Ω. B. It is strictly prohibited to use gas pipes as protective conductors. C. The grounding grid of 35 kV substations should be connected underground to the grounding electrodes of the incoming lightning protection wires; the length of the connection wires should be no less than 30 m. D. The PEN conductor in TN-C and TN-C-S systems must be insulated according to the highest voltage it may be exposed to
Regarding grounding, it has always been unclear; I came here to learn about it.