Analysis of Common Faults of Electric Hoist and Suggestions for Improvement
Causes of electric hoist failure The mobile flexible cable breaks: the reason is that the cable is fatigued and aged under multiple cycles of stress and high temperatures. Control cable disconnection: due to the long control cable and the large moving distance of the electric hoist, disconnection, and loosening of wiring are often caused by the operator’s tugging. The contactor contacts are burned out. For motors that repeatedly work for short periods of time, the equivalent heating current is too large. In addition, during the conversion process, the phase commutation is too fast, and the arc freewheeling of the contactor can easily cause a phase-to-phase short circuit and burn. Bad contactor contacts. For general motors, the operating current is less than the rated current. Although the starting current is 4 – 7 times the rated current, the time is short after all, and the damage to the contacts is not great. When designing the contactor, as long as the contact capacity is greater than the rated current of the motor 1.25 times is sufficient. However, the electric hoist motor is a motor with special working conditions, such as frequent starts and stops under heavy loads, reverse braking, poor heat dissipation,...
