We have seen many applications of variable frequency motors, and their performance is very excellent. However, some users may report that the variable frequency motor may experience vibration and noise during operation. Is this a normal phenomenon? This requires further analysis.
If the vibration and noise emitted by the variable frequency motor are not very strong or loud, it is still relatively normal; But if the vibration is strong, the sound is too loud and fluctuates high and low, it is considered abnormal. And there are many reasons that can cause this phenomenon, such as:
1. The uneven air gap of the motor can cause electromagnetic noise. If it is due to the uneven air gap, the fault can be checked from aspects such as the deviation of the bearing frame, the deformation of the base caused by the sinking of the foundation, and the wear of the bearings.
2. Imbalance of current is a situation similar to uneven air gap, which occurs at a frequency of twice the power supply frequency. We should identify the cause from factors such as voltage imbalance, coil grounding, wire breakage, short circuit, or rotor circuit impedance imbalance, poor contact, etc.
3. Loose iron core is also a very common cause, as vibration and temperature fluctuations during motor operation can cause thermal expansion and contraction, which can loosen the clamping bolts of the iron core, making it prone to vibration and increasing electromagnetic noise.
Besides these, there must be other reasons. We just need to remember that if the variable frequency motor encounters a malfunction or abnormal situation, it should be stopped immediately for inspection, and it must wait for everything to return to normal before restarting.