Industrial Crane grounding requirements
① grounding range; Industrial Crane all the electrical equipment on the normal uncharged metal shell, metal wire, cable metal sheath, safety transformer low-voltage side of the end should be a reliable grounding.
② grounding structure: the Industrial Crane allows the use of metal structures for grounding, metal structure must be a reliable electrical connection as a whole. If there is a non-welded joint in the connection of the metal structure, a separate trunk or jumper wire shall be provided separately. Grounding wire connection is not suitable for cross-sectional area of not less than 150mm2 flat steel or 10mm2 copper wire. The connection of the grounding wire to the equipment can be made by welding or bolting. The bolts shall be connected with anti-loose and anti-rust measures. When the driver’s room and the Industrial Crane body are bolted, the electrical cross-over shall adopt the multi-strand soft copper wire, the cross-sectional area shall not be less than 16mm2, and the crimp terminals shall be fixed with galvanized bolts at both ends. When the flat steel or round Steel cross, the flat steel should be not less than 40 × 4mm, round steel diameter had to be less than 12mm. The cross-connect should be no less than two. A Industrial Crane working on a track can generally be grounded by wheels and rails. If necessary, should be a special grounding slip line or take other effective measures.
③ grounding resistance: the Industrial Crane each track, should be located two ground, the joints between the track should be used for electrical cross. Track and any point on the Industrial Crane grounding resistance shall not be greater than 4Ω. Zero line is not more than 10Ω when grounded.