With the increase of high-rise buildings and the usage of elevators, the overall failure rate of elevators has further increased. Therefore, it is required that debugging and maintenance personnel can quickly eliminate faults in a short period of time, reduce the downtime of elevator failures, and improve the utilization rate of elevators. Here, I will briefly introduce several quick diagnosis and solution methods for elevator faults.
1、 Fault phenomenon:
The elevator cannot operate normally. When walking slowly in the car, the elevator shakes and runs at a very slow speed. Observe the elevator crawling in the machine room.
2、 Fault analysis:
1. The speed generator or rotary encoder is damaged. Measure the input and output voltage of the encoder. If the voltage is normal, it may be due to external impact on the encoder, causing the position of the grating to shift. Or due to scratches on the encoder grating, the encoder cannot output pulses normally.
VVVF control elevator main motor phase failure. One phase of the internal coil or external connecting wire of the main motor is burnt.
The main circuit current transformer and voltage transformer (usually using Hall sensors) are damaged. The current and voltage transformers are not outputting or the output does not meet the requirements, and the main computer cannot receive voltage and current feedback signals.
4 VVVF elevator main motor or rotary encoder connected incorrectly. (Baidu search for Mozhe Blog) During the debugging process, the three-phase wires of the main motor were connected incorrectly, or any two phases of the rotary encoder were connected incorrectly.
There are debris between the stator and rotor inside the motor. The motor may become damp, rust inside, or foreign objects may fall into the motor.
3、 Fault handling:
Replace the rotary encoder.
Measure the insulation of the motor with an insulation meter. If the insulation is normal, only the external wiring has been burnt. Reconnect it, but pay attention to the wire bait at the connection end; If the insulation is abnormal, the motor is damaged and needs to be rewound or replaced.
Replace the transformer.
Adjust the connection wires of the motor and encoder, paying attention to coordinating the adjustments.
5. Disassemble and clean the motor as a whole. If the insulation is normal after cleaning, it can continue to be used