installation gantry crane
Seven important safety issues in the installation gantry crane
About the electrical safety of gantry crane frame
More of the installation gantry crane frame is at the end of the main stage of the building, the tower crane demolition, construction site temporary power at this stage management is lax. The main problems are as follows:
- Hoist under the fuselage not meet PE line, or although have PE line, but it is not firm, loose, meet zero protection effect is not guaranteed.
- Hoist do not repeat grounding, even if there, some grounding is not according to the specifications and round or angle, Instead of using steel, the grounding resistance is not up to the specified value.
- There is no isolating switch in the switch box, and can not use the electric equipment to carry out the power isolation during the daily maintenance and maintenance. Switch of the leakage protector in the leakage current action is larger, Not in accordance with the norms of rated leakage action current 30mA, rated leakage action time 0.1s to choose, etc.
- When the gantry lifting standing gantry crane material, the material is not fixed on the hanging, in operation, the interference between frame and body. And not prevent slip (roll) material.
- The tests also found, when the gantry crane drops, some hoist operation by rolling, is a serious illegal operation. 《Construction winch – Safety Rules》Prohibit the use of human power control to implement open brake rolling, is a serious illegal operation. 《Construction winch – Safety Rules》It is strictly prohibited to use human open power control “, otherwise, the brake running due to landing speed, brake run and other factors, will cause damage to basket, basket derailment, frame body deformation and welding equipment for personal accident.
- Winch operator from machine, hanging basket fell to the ground, cut off power supply.
- Winch operator of the steel wire rope on the drum is arranged neatly in the case not corrected, causing the wire rope load after mutual extrusion, die bending, cable extrusion, rope structure damage, thus destroying the force of wire rope.