How to diagnose and respond to noise
when the motor is running
 
a) Rotor rubbing slot insulation or slot wedge makes a rustling sound, if the insulation at the end of the winding is too long, it can make a puffing sound, trim the excess part of the insulation paper and overhaul the higher part of the slot wedge than the core.
 
b) Bearing lack of oil or failure
Bearing lack of oil, should clean the bearing, fill with grease. If the bearing is damaged, it should be replaced with a new one.
 
c) Loose stator and rotor cores and internal and external fans
Need to re-tighten the core, rotor bracket rotor should be checked whether the rotor bracket and the rotor shaft with loose ring key is open welding: inside the fan and the shaft with the size of whether too loose or not card tight.
 
d) winding failure
Mainly check whether the winding is wrongly connected or whether there is a short circuit.
 
e) Power supply voltage is too high or the three-phase voltage is unbalanced
Use a voltmeter or multimeter to check the cause of high voltage and unbalance and then deal with it according to the actual situation.
 
f) Fan touching the end of the lookout or air duct blockage repair the fan and end cover, so that its geometry to restore the original; clear the ventilation channel obstacles.
 
g) Uneven air gap or foreign matter in the motor cavity need to find out the reason to adjust the air gap; clear the foreign matter in the cavity.