Experts point out that the common fault diagnosis and treatment of single-phase motors are dry goods!

1 The power supply voltage is normal, the motor does not start after power-on.

1) The power wiring is open (the motor is completely silent). There should be no voltage across the measurement terminals.

2) The main winding or auxiliary winding is open. The method of measuring the DC resistance can be used to determine whether or not the circuit is open.

3) The centrifugal switch contact is not closed, so that the auxiliary winding can not be energized. The connection point of the main winding and the auxiliary winding is disconnected, and then the method of measuring the DC resistance can be determined.

4) The start capacitor wiring is open or internally open. The search method is the same as item 3) above.

5) Open/drop the shaded pole motor (shade ring). For the short-circuit ring to set the outside can be seen, often through observation can be found.

6) For the series-excited motor, the brush cannot be connected to the commutator due to the short brush or jam, or the brush lead is disconnected, or the armature winding or the field winding is open internally.

Experts point out that the common fault diagnosis and treatment of single-phase motors are dry goods!

2 The power supply voltage is normal. After the power is turned on, the motor rotates at a low speed. There is a “beep” sound and vibration, and the current does not drop.

1) The load is too heavy.

2) The stator and rotor of the motor are rubbed. An abnormal rubbing sound will be emitted.

3) The bearing is stuck due to poor bearing assembly, grease consolidation in the bearing, bearing roller bracket or roller damage.

4) For series-excited motors, short-circuit between commutating segments or internal short-circuit of armature windings, or excessive deviation of the brush from the centerline (motors that can move the brush).

3 After the power is turned on, the power fuse is blown quickly

1) A severe short circuit between winding turns or ground. Measure the DC resistance. If the value is much smaller than the normal value, it is the short circuit between the windings. The severe short circuit to the ground can be measured by the insulation resistance meter or the high resistance file of the multimeter (such as R&TImes; 1k). The current will be greater than the rated value.

2) The motor leads the phase line to ground. The inspection method is the same as the fault item 1).

3) The capacitor is shorted. This is determined by measuring the DC resistance between the ends of the start winding circuit (including the capacitor and the start winding, excluding the centrifugal switch) with a lower resistance of the multimeter (eg R&TImes; 1).

4) The centrifugal switch is shorted to ground. The inspection method is the same as the fault item 1).

5) The load is too heavy. The sound will be abnormal and the current will be greater than the rated value.

4 After the motor starts, the speed is lower than the normal value.

1) The main winding has a short circuit to the ground or to ground. The inspection method is the same as item 1 in item 3.

2) There is a coil reverse connection fault in the main winding. The sound will be abnormal and the current will be greater than the rated value.

3) The centrifugal switch is not disconnected, so that the auxiliary winding cannot be disconnected from the power supply. The current will be greater than the rated value.

4) Heavy load or bearing damage. The sound will be abnormal and the current will be greater than the rated value.

5) For series-excited motors, short-circuit between commutating segments or internal short-circuit of armature windings, or poor contact between brushes and commutators.

5 When the motor is running, it will heat up very quickly

1) The winding (including the main winding and the auxiliary winding) is short-circuited between turns or ground. The inspection method is the same as item 1 in item 3.

2) There is a short circuit fault between the main winding and the auxiliary winding (other than the end connection point). The current will be greater than the rated value.

3) After starting, the centrifugal switch is not disconnected, so that the auxiliary winding cannot be disconnected from the power supply. The current will be greater than the rated value.

4) The main winding and the auxiliary winding are connected to each other for the motor that operates mainly or only the main winding (the single-phase split-phase motor other than the single-valued capacitor motor whose two windings are identically activated and operated). The current will be much larger than the rated value.

5) The working capacitor is damaged or the wrong capacity is used.

6) Fixed, rotor core rubbing or bearing damage. The sound will be abnormal and the current will be greater than the rated value.

7) The load is heavy. The current will be greater than the rated value.

8) For series-excited motors, short-circuit between commutating segments or internal short-circuit of armature windings, or poor contact between brush and commutator.

6 Motor running noise and vibration are large

The noise and vibration (especially vibration) of a single-phase motor is relatively large compared to a three-phase asynchronous motor of the same capacity or the same frame number. This is because its stator rotating magnetic field is not a regular circular shape, so the torque will not be equal at all times, that is, there will be fluctuations in size within one circumference, causing radial vibration of the rotor.

Common causes of loud noise and vibration are as follows:

1) Poor immersion paint, causing looseness between the core sheets, resulting in higher frequency electromagnetic noise.

2) The centrifugal switch is damaged.

3) Bearing damage or excessive axial turbulence.

4) The air gap is uneven or axially misaligned between the stator and the rotor.

5) There is foreign matter inside the motor.

6) For series-excited motors, short circuit between commutating segments or internal short circuit of armature windings, or poor contact between brush and commutator (mica between commutator segments is higher than commutator segments or commutator segments, or brush is too hard , too much pressure, etc.).

Mobile Accessories

Mobile Accessories,Wired Headset,Usb Fan,Usb Drive

Shenzhen GEME electronics Co,.Ltd , https://www.gemesz.com

Posted on