(2) The grounding branch lines shall be directly connected to the terminals of the grounding trunk line respectively, and shall not be connected to each other before grounding.
(3) The main power switch should not cut off the following power circuits;
① Automobile lighting and ventilation.
② Lighting between machine room and pulley.
③ Power sockets for machine room, car roof and pit.
④ Good lighting.
⑤ Alarm device.
(4) Flexible wires and unsheathed cables should be used in conduits, trunking or devices that can ensure the same protection. Sheathed cables and soft rubber cables can be used in mines or computer rooms, but not on the ground.
(5) The laying of conduits and trunking shall be neat and firm. The total area of wires in trunking shall not be greater than 60% of the net area of trunking; The total area of wires in the conduit should not be greater than 40% of the net area in the conduit; The fixed spacing between the piano tubes should not be greater than 1m, and the fixed spacing between the two ends should not be greater than 0.1m.
(6) Yellow-green insulated conductor shall be adopted for grounding branch line.