Ground structure: the metal structure is allowed to be grounded on the crane, and the metal structure must be the integral of a reliable electrical connection. If the connection of the metal structure is not welded, the connection shall be grounded. The ground connection is not less than 150 mm2 flat steel or 10mm2 copper wire. The connection of ground wire to the equipment can be welded or bolted, and the bolt connection should be used for the protection of loose and anti-rust measures. Driver chamber and a crane ontology with bolt coupling, the two electric jumper appropriate USES soft copper wire, the cross-sectional area shall not be less than 16 was, crimping terminal should use galvanized bolts on both ends fixed; When using flat steel or round steel, the flat steel should not be less than 40x4mm, and the diameter of the round steel should be less than 12mm. There should be no less than two contact points. Cranes that work in orbit are generally grounded in the wheels and tracks. Special ground or other effective measures should be established when necessary.
Ground resistance: the crane is on each track, should be set two ground, the connecting head of the orbit is suitable for electric span. Any point on orbit and crane, the grounding resistance shall be greater than 4 Ω. When multiple grounding is not greater than 10 Ω zero line.
Grounding; Crane and all electrical equipment normal not charged metal shell, metal wire tube, cable metal sheath, security transformer low voltage side end shall be reliable grounding.
