electric hoist is hard to avoid failure in using process. It has become an important part of construction production to improve the safe operation of electric hoist, solve all kinds of faults occurred timely and accurate in the use of processing.Combined with the experience in installation and maintenance, we have specific analysis of the causes of some common faults of electric hoist.
Many faults of electric hoist often accompanied by abnormal noise such as electric control,motor or reducer . The distinct of the noise of the location ,the level and tone is different with the cause of the malfunction . See and hear more when overhaul, You can use the sound characteristics to determine the position, find and repair the malfunction.
(1) the abnormal noise of a "hum" occurred in the control loop is generally contactor has failed (such as contact of AC contactor is bad contact, can not match the voltage level, the cores are get stuck, etc.), It must be replaced to deal with fault contactor for maintenance when unable to repair ,and the noise eliminate on their own after-treatment .
(2) It should immediately shut down when motor make abnormal noise, check whether the motor running single phase, or bearing damage, coupling axis is not straight, and the chamber "sweep", these will make the machine has abnormal noise.the sound of different fault is different from location, level and tone. When single-phase operation, the entire motor makes regular suddenly strong suddenly weak "buzzing" sound; while bearing damage, issued along with the "thump - thump" of the "buzz" sound in the vicinity of the bearing; but when the axis of the coupling is not straight or motor slight sweep chamber, the entire motor makes high "buzzing" sound, accompanied by a shrill voice occasionally. In a word, we should find fault and itemized repair to restore normal performance of the motor according to the different noises, it is prohibit to use hoist when the motor fault untreated.
(3) the abnormal noise emitted from the gear reducer, gear reducer failure (such as reduction gearbox or bearing lack of lubricant oil, wheel gear abrasion or damage, bearing damage, etc.), then you should stop to check.The first thing is to ensure the speed reducer gearbox or bearing whether add lubricant oil before using, oil change regularly in use, if not required lubrication, the gear reduction will not only generate excessive "buzzing" sound and the gears and bearings also excessive wear or damage .
Should first check whether the hoist overload to use, resulting in motor overload fever, long-term overload will burn motor; if the motor is not overloaded but still hot, you should check whether the motor bearing damage and also check the motor is required to work the system to work, which is one reason to cause the heat of the motor . The motor should be used in strict work duty. When the motor is running, the brake gap is too small, not fully disengaged, have a great friction, the friction heat also is equivalent to increase the additional load, the motor speed is reduced, the electric current becomes large and emit heat, you should stop working right now, and to adjust the brake clearance.
Such cases are generally contactor contact fusion welding .When the stop switch is pressed, contactor contacts can not be disconnected, electric motor was running as usual, hoist don’t parking; to the extreme positions such as limit is out of order, hoist don’t parking. When this happens, immediately turn off the power, make hoist force to stop. After parking, maintenance contactor or stopper. if the hoist serious damage and can not be repaired .It must be replaced and so is miniature electric hoist .
In winter construction, circuit is trouble-free and the motor still can not start especially after the snow, the reason is brake ring freeze to death.if this time forced to boot, it is easy to burn the motor. The solution is to open the motor cover, move the motor with a crowbar so that it can rotate freely.
The reason for the stroke limiter is damaged, need to change the stroke limiter and so does chain hoist .
Through the analysis of electric hoist common faults and processing, make the hoist maintenance staff know where to start to check and improve the efficiency of maintenance when they deal with failure.In addition,it also provides the operator with the method to deal with problems.
