Due to the fact that the resistance group in the resistance box of the crane is mostly in operation during normal operation, a large amount of heat is generated, resulting in a higher temperature of the resistance group. In high temperature environments, both the resistor itself and the resistor connection terminals are prone to deterioration.
At the same time, the switching frequency of various AC contactors in bridge cranes is particularly high during operation. Its contacts are easily damaged and aged during frequent switching, causing some contacts to have increased contact resistance or phase loss, resulting in an unbalanced series resistance of the motor winding. This can lead to motor damage and failure when the crane is overloaded or working for a long time.
Whether it is an imbalance in the series resistance of the motor or an imbalance in the three voltages, the motor will produce abnormal sounds and other abnormal phenomena, whether long or short, strong or weak. If the driving motor generates a high temperature rise in a short period of time, the motor will shake violently, and the crane may experience a "powerless" phenomenon. The brake pads of the motor will collide with each other, producing high-frequency and unstable friction sounds, and over time, motor damage may occur. At this point, the machine should be stopped immediately for timely maintenance and inspection.
To prevent such accidents, regular maintenance workers should be organized to inspect and maintain the resistance box and control box. Strengthen the inspection of vulnerable components in the power supply sliding contact line system, and promptly repair or regularly replace the current collector. Regularly or frequently check the status of the sliding wire guide rail and fork, adjust the floating suspension clamp to allow the conduit to expand and contract freely. In addition, it is necessary to regularly check the fixing bolts and wiring terminals of electrical components, and install spring pads or anti vibration rubber pads. Reasonably arrange the power supply circuit of the crane during installation, and avoid connecting other high-power power supply equipment on dedicated circuits.
Post time: Sep-29-2024
