Motor common fault analysis and maintenance - electrical fault

Electrical failure of the stator windings without phase operation,the reverse of the stator winding unbalanced three phase current,winding short circuit and grounding,heating winding and rotor broken bar,open circuit,etc.Lack of phase operation is one of the common faults.As long as there is a phase in the asynchronous motor three-phase power supply circuit can cause motor open phase running.Lack of phase operation may be due to line fuse melt fuse,switch contact or wire connector causes such as poor contact.When the power is short of a three-phase motor phase,such as in stop state,due to the synthesis of zero torque and blocked,the inability to start).The locked-rotor currents of the motor current is much larger than normal work.Apply generator generator set power,therefore,in this case the time is too long or more frequent start turning on the power supply will lead to motor burn down.

Running motor is short of a phase,such as load torque is small,still can maintain operation,only speed decreases slightly,and abnormal noise; When the loads,the operation time is too long,will make the motor winding burn.Three-phase winding fore and electricalmotor1.blogspot.com aft misconnect when,after turning on the power supply will be three phase current serious imbalance,reduced jumps,vibration,temperature rise of the rotating speed,the phenomenon such as voice radically.If not protection device,it is easy to burn out motor winding,so must see first,tail motor wire end,before electricity operation.Three phase current unbalance fault,often caused by motor external power supply voltage imbalance,the motor parts internal reason mainly is the winding interturn short circuit or in motor rewind coil number of turns or wiring errors when repaired.Winding grounding and short circuit current is too large.Ground fault available megohmmeter.Can reduce in the stator winding voltage short-circuit fault case,judged by measuring the current,can also measure the dc resistance to judgment.