Electrical network & # 8203; An aspect, the power supply problem power motor overheating occurs reason, have the following kinds: 1, the power supply voltage is too high when the supply voltage is too high, the counter electromotive force of the motor, the magnetic flux and magnetic flux density increase. Because the basis of iron loss and magnetic flux density is proportional to square, add the iron loss and lead to core overheating. And magnetic flux to add, causing a significant added field current weight and formed stator winding copper loss increase, make the winding overheating. Therefore, an extra voltage supply voltage beyond the motor, motor overheating. 2, low voltage power supply voltage is too low, if the electromagnetic torque of the motor remains unchanged, flux will decline, the rotor current increases accordingly, stator current load in the power supply then add weight, form the copper winding loss increase, cause, rotor winding overheating. 3, power supply voltage asymmetry when the power cord phase circuit, a fuse, fuse or knife starting equipment led to a phase Angle head burns impassability, will form a single-phase, three-phase motor in operation of two phase winding overheating by high current, but when burned. Therefore, generally does not apply to fuse for maintenance of three-phase motor. 4, unbalanced three-phase power source when unbalanced three-phase power, can make the unbalanced three phase current of the motor, causing winding overheating. From the above, when motor overheating, should first consideration of the reasons of the power supply (Soft start, inverter, servo drives can also be regarded as the power supply)。 Confirm the power aspects have no problem, then to consider other factors. Second part load problem, load the motor overheating the reason has the following kinds: 1, motor overload operation when the device does not form a complete set, the additional load power is greater than the motor power of the motor, electric machine long time overload running (The little horse cart), can lead to overheating. Repair motor overheating, should first find out whether the load power and motor power, in order to prevent blindness apart without a purpose. 2, drag the mechanical load operation is not normal while supporting equipment, but the mechanical load that drag operation is not normal, operation load when small, motor overload and fever. 3, drag the machinery fault when being dragged mechanical failure, or stuck, not flexible rolling will make the motor overload, form the motor winding overheating. So the repair motor overheating, load factor cannot be ignored. 3, question 1 motor itself, motor winding circuit when there is a phase winding break in the motor winding, or parallel branch has a branch circuit, will lead to unbalanced three phase current, overheat the motor. 2, motor winding short circuit when the present motor winding short-circuit fault, short-circuit current is much bigger than normal operation current, add the winding copper loss and cause the winding overheating, even burned down. 3, star of the motor Angle connection error when misconnect into star delta connection motor, motor with full load operation, still flows through the stator winding current to go beyond the additional current, even cause the motor to parking, if a halt time slightly long, did not block the power supply, winding is not only serious overheating, will also be burned. Misconnect when star connection of motor into a triangle, or several coil string into a branch set of motor fault into two branch in parallel, will overheat the winding and iron core, serious when will burn winding. 4, motor coil connection error when a coil, the coil group or a phase windings to reverse, will lead to serious unbalance of three phase current and make the winding overheating. 5, the mechanical failure of the motor when the motor shaft, gear owe good, bearing fault, etc. , all can make the motor current increases, conflict of copper loss and machine loss to add, make the motor overheating. Four, electric fan thermal dissipation 1, the environment temperature is too high, the inlet air temperature is high. Debris blocking is 2, air inlet, so that poor into the wind, little formation into the wind. 3, the motor internal dust too much, the impact of heat dissipation. 4, fan damage or installed backwards, forming no wind or air volume is small. 5, not installed wind cover or inside the motor end cover not installed wind deflector, form a motor without a certain wind path. Five, repair electrical repair the motor start current is more than 66%, motor operation frequently at the same time, also can form high current, motor overheating. Six, wound rotor motor series resistance problem with concatenated resistor mismatch, such as motor work frequently at the same time, also can form high current, motor overheating. Oscillation of motor vibration is too large, also may form the motor current is high, the cause and the solution: 1, the rotor unbalance & ndash; —Leveling balance 2, imbalance of pulley or winding shaft extension & ndash; —Review and correction 3, the motor is not aligned to the load axis & ndash; —View to adjust the axis of the unit 4, improper motor device & ndash; —Check device status and 5 foot screw, the heavy load suddenly & ndash; —Lighten the load
