Cause of excessive motor current

Update:09 Mar 2019
Summary:

Motor itself problem 1, motor winding open circuit When […]

Motor itself problem

1, motor winding open circuit

When one phase winding in the motor winding is open, or one branch in the parallel branch is open, the three-phase current will be unbalanced and the motor will overheat.

2, motor winding short circuit

When the motor winding has a short-circuit fault, the short-circuit current is much larger than the normal operating current, which causes the winding copper loss to increase, causing the winding to overheat or even burn out.

3, motor star angle connection error

When the delta connection motor is connected in a star shape, the motor is still running at full load, the current flowing through the stator winding exceeds the rated current, and even the motor stops by itself. If the stall time is longer and the power is not cut off, the winding is not only serious. Overheating will also burn out. When the star-connected motor is misaligned into a triangle, or a plurality of coils are wired into a branch, the motor is misconnected into two branches in parallel, which will overheat the winding and the core, and will burn the winding in severe cases.

4, motor coil connection error

When a coil, a coil group or a phase winding is reversed, it will cause a serious imbalance of the three-phase current and overheat the winding.

5, the mechanical failure of the motor

When the motor shaft is bent, the assembly is not good, and the bearing is faulty, the motor current is increased, the copper loss and the mechanical friction loss are increased, and the motor is overheated.