Single-phase asynchronous motor refers to
the single-phase stator winding and single-phase AC power supply asynchronous
motor. It is a derivative of squirrel cage three-phase asynchronous motor, with
the basically same structure with squirrel cage three-phase asynchronous motor and the rotor is also squirrel cage type. Therefore, the elimination method of
faults, such as winding short circuit, circuit break, grounding, wiring error,
motor overheating and so on is basically the same as the three-phase
asynchronous motor.
Although single-phase asynchronous motors
and three-phase asynchronous motors are basically the same, there are five
major differences:
1. The stator winding of single-phase
asynchronous motor has only the main winding and the secondary winding. The
polar group of the main winding and the secondary winding is symmetric, but the
polar group between the main winding and the secondary winding of washing
machine is not necessarily symmetric. The stator windings of three-phase
asynchronous motor are symmetrical windings A, B and C3.
2. The stator windings of the primary and
secondary windings of the single-phase asynchronous motor are basically
separated by an electric degree Angle of 90°. The electrical angle between the
primary and secondary windings is slightly greater than or less than 90°, which
is different from the strict requirements for three-phase asynchronous motor
windings. This has little effect on single-phase AC motors. The three-phase
stator windings of three-phase asynchronous motors A, B, and C must be
spatially separated by an electrical angle of 120°.
3. The stator winding of single-phase
asynchronous motor adopts the method of two-plane embedding, that is, the main
winding is embedded first, then the main winding is embedded in the outer
layer, and then the secondary winding is embedded in the inner layer. The
embedded wire is simpler than the three-phase asynchronous motor winding.
Handle embedding is usually used in the three-phase stator windings of
three-phase asynchronous motors.
4. The wire diameter of the secondary
winding of single-phase asynchronous motor is thinner than that of the main
winding, so it is easy to burn out. If burned, all or part of the secondary
windings can be replaced. The stator windings of the three-phase asynchronous
motor need to be replaced by all the windings as a unit because the hanging
handle is embedded.
5. The winding structure of single-phase
asynchronous motor is more complex than that of three-phase asynchronous motor.
The main and secondary windings have different wire diameters, and the number
of coil turns in the same polar phase group is not necessarily the same. The
starting method is different, and the winding forms are different. And the
three-phase asynchronous motor three-phase winding is in accordance with the
national unified design standard production, in accordance with the unified
technical specifications, in the maintenance process to follow certain rules,
so it is not easy to make mistakes.