The tower crane shall not use aluminum conductor and screw steel as grounding body or underground grounding wire. Wires connected with bolts must have one end. There are three main ways to ground:
1. The grounding body adopts regular grounding pile, or 33 * 4.5 long 1.5m steel pipe, or 70 * 70 long 1.5m angle steel.
2. The grounding plate is made of steel plate or other extendable metal plate with an area of 1 square meter. Standing 1.5m deep from the ground.
3. A copper conductor with a cross-section of not less than 28 mm, or a steel conductor with a cross-section of not less than 50 mm is buried in the wire groove, and the buried length is determined by the grounding resistance.
In the above three methods, the cross-sectional area of the copper wire leading from the grounding body should not be less than 25. If the soil has poor conductivity, sodium chloride (table salt) can be buried in the soil. Then irrigate. For walking tower cranes, each rail must be grounded, and a wire connection should be used between the two rails. Electrical connection should also be made between the two steel rails, and the grounding resistance is not greater than 4.
