For the specific test of electric hoist overspeed protection device, there are two ways in China at this stage:

A: the key detection is not to set the overspeed protection device, manual to make the overspeed protection device posture, query the equipment operation, the motor is not off the power, the brake system is not the brake system. This kind of inspection method only carries out the inquiry to determine the automatic control system of electrical equipment, and does not determine whether the posture or speed of the overspeed protection device is in line with the provisions of 1.25-1.4 times rated rate in the whole process of specific use when the motor is really overspeed, thus leaving safety risks.

Two: at this stage, the main lifting equipment overspeed protection device is mostly used in crane lifting organization. The overspeed protection device calibrator developed and designed by each gearbox jack manufacturer and testing center is all for this kind of device. Is it possible to remove the overspeed protection device from the crane and install it on the calibrator to achieve speed check? This method can accurately measure the speed of overspeed protection device, but the overspeed device must be removed from the crane, and then assembled on the calibrator to achieve accurate measurement. This kind of way is not suitable for galvanized wire rope electric hoist, galvanized wire rope electric hoist overspeed maintenance initialization failure inspection method. Ac contactor and small relay flutter bounce: fully consider the harm of calcium carbide dust to the body, calcium carbide feeding has two methods of local and long-distance remote control operation. Long-distance remote control operation is to operate the calcium carbide feeding operation according to the TV monitor in the main control room with the cross power switch on the stage.

Solution: multi-functional jack manufacturers to reduce the loss on the route, the immediate way is to reduce the length of the frequency conversion cable. Pneumatic jack manufacturer specific use, reduce the ac contactor bounce caused by the main circuit breaker damage.

Check current status of jack manufacturer electric hoist overspeed protection device