Crane descending overspeed solution

In fact, descent overspeed is generally due to improper operation, or the lifting object is overweight, resulting in overspeed in the process of descent. The high-speed shaft end of the hoisting mechanism is equipped with an overspeed switch. When the speed of a single machine exceeds 115% of the rated speed, the whole machine will stop urgently.

For the lifting mechanism, when the main order enters other gears from down 4 gears, the load continues to drop rapidly, and the speed exceeds 130% of the synchronous speed, and the controller will immediately block the output. Possible causes and troubleshooting methods. The motor torque is suddenly insufficient. It may be that the power supply voltage is too low during this period, the load weight greatly exceeds the rated load weight of the motor, and the motor rotor is open in one or two phases.

This control device is widely used in hoisting mechanisms such as bridge cranes, portal cranes, gantry cranes, tower cranes, loading and unloading bridges, mine hoists, etc. The simple and composite models can fully meet various tonnages and various occasions. Needs.

When the crane is running on the line without obstacles, the hook or spreader and the bottom surface of the hanging object must be at least 2m above the ground. If you cross the obstacle, you must exceed the obstacle by 0.5m.

For lifting objects less than 50% of the rated lifting weight, two mechanisms are allowed to operate at the same time; for lifting objects greater than 50% of the rated lifting weight, only one mechanism can operate.

only after the power outage, and when there is a power outage operation sign hung on the switch, can the inspection or maintenance work be carried out. If it is necessary to work with electricity, it must be protected by safety measures and has a special person to take care of it.