Large tonnage gantry crane has been in field construction for a long time, and the construction site is mostly open area. When encountering thunderstorm weather, the towering boom is easy to become the lead down channel of lightning, so that the machine is struck by lightning. If the crane lightning accident, light cause electrical damage, heavy cause safety accidents, so do a good job of portal crane lightning protection work is very necessary.
According to the lightning damage to equipment, can be roughly divided into two categories, namely direct lightning damage and induction lightning damage, lightning strike damage electric effect, main show is in the machine, thermal effect and mechanical force lightning discharge damage, often show the damage of the mechanical structure, surface ablation, and visible in the air or discharge to the ground. Inductive lightning damage is mainly caused by the strong electromagnetic field of lightning discharge, which generates electrostatic induction or electromagnetic induction overvoltage and overcurrent in the adjacent wires and electrical equipment system, resulting in damage to the interface components of electrical equipment and electronic equipment.
Outdoor gantry crane lightning protection is mainly the following aspects: 1. In view of the gantry crane is all metal materials, so can not consider direct lightning protection; 2. Ground properly. 3. Make equipotential connection between equipment and crane; 4. Protect the power supply.