For liming motor, the following hazards may occur when […]
For liming motor, the following hazards may occur when the operating voltage exceeds the allowable range:
1. When liming motor starting, the power supply voltage drops too much, the start is slow or even unable to start. For asynchronous motors, the starting torque is proportional to the square of the voltage. The voltage is reduced by 10% and the starting torque is reduced by 20%.
2. During operation, when the voltage is low and the load remains unchanged, the speed will drop (or even stop), the motor current will increase, the motor will overheat, affect life, and even burn. Voltage distortion: The voltage waveform deviates from the normal sine wave. Common waveform spikes and electrical noise interference in the voltage.
3. Voltage waveform spike refers to a short-term shock that exceeds the normal voltage. The small spikes of low energy mainly come from the switch of inductive load, which is a common phenomenon in factories. The larger spike is mainly caused by the flashover discharge transmitting on the power line. The duration is extremely short, and the peak value can reach 5 to 10 times the normal voltage. It may cause the data stored in the control device to be lost or cause misoperation, or it may immediately cause damage to the equipment or random damage that is difficult to detect.
4. Electrical noise (currently a more common form of power disturbance, it may be easier to correct. But it is difficult to detect it) Voltage spikes with lower amplitude will cause electrical noise interference. The emission of radio waves, computers, business machines, etc. and even poor electrical connections can produce electrical noise. It will cause the computer to malfunction, and the mutual electromagnetic interaction between the various components of the control equipment may generate a sufficiently large electrical noise, resulting in operational errors. Although most devices are equipped with filters, they should still avoid working in environments with severe electrical noise.
5. Short-term interruption of power supply only a short interruption of 5ms may stop the work of some sensitive electrical equipment. For users, the trouble is that the data stored in the control device is lost or it takes time to reprogram.