Hot Selling YL Single Phase Asynchronous Motor

• The power supply wiring is open circuit (the motor is completely silent). Measure the voltage at both ends of the terminals.
• The main or auxiliary winding is open. Measure the DC resistance to see if it is open.
• The centrifugal switch contact is not closed, so the auxiliary winding cannot be energised. Disconnect the main winding and auxiliary winding connection point, and then use the method of measuring DC resistance can be determined, you can also use the second part of the method to determine.
• Start capacitor wiring open circuit or internal disconnection. Use the same method as in point 3) above.
• For shaded-pole motors, the shaded-pole coil (shading ring) is open or disconnected. For the shading ring can be seen outside the installation, often can be found by observation, otherwise can be used in the second part of the method to determine.
• On series-excited motors, the brushes are off or cannot make contact with the commutator because the brushes are too short, stuck, etc., or the brush leads are disconnected, or the armature windings or magnetic field windings are internally open-circuited.

• The load is too heavy.
• The motor stator and rotor are rubbing against each other. There is an abnormal friction noise.
• Bearing seizure due to poor bearing fitting, solidified grease in the bearing, bearing roller support or broken roller.
• For series-excited motors, a short circuit between the commutator plates or within the armature winding, or brushes too far off centre (for motors with moving brushes).

• Serious short-circuit between windings or to earth. Measure the DC resistance, if the value is much lower than normal, it is a short circuit between turns of the winding; a serious short circuit to ground can be used to determine the insulation resistance meter or multimeter higher resistance file (such as R × 1k file) for measurement. The current will be higher than the rated value.
• Motor lead phase wire is earthed. Check in the same way as fault 1).
• Capacitor short-circuited. Determine by measuring the DC resistance between the two ends of the starter winding circuit (including the capacitor and starter winding, excluding the centrifugal switch) with a multimeter at a lower resistance setting (e.g. R x 1).
• The centrifugal switch is short-circuited to earth. Check as in point 1).
• Excessive load. The sound is abnormal and the current is higher than the rated value.

• There is a rotation or short-circuit fault in the main winding. Check as in point 3.
• There is a winding reversal fault in the main winding. The noise is abnormal and the current is higher than the rated value.
• The centrifugal switch is not disengaged so that the auxiliary winding cannot be disconnected from the power supply. The current is higher than the rated value.
• Heavy load or bearing damage. The noise is abnormal and the current is higher than the rated value.
• In the case of series-excited motors, a short circuit between the commutator plates or inside the armature winding, or poor contact between the brushes and the commutator.

• Winding (including main and auxiliary windings) has interturn or short circuit to earth. Check as in point 3.
• There is a short-circuit fault between the main and auxiliary windings (except at the end connection point). The current is higher than the rated value.
• The centrifugal switch is not disengaged after starting, so that the auxiliary winding cannot be disconnected from the power supply. The current will be higher than the rated value.
• In the case of motors which operate mainly or exclusively on the main winding (single-phase split-phase motors, with the exception of single-value capacitor motors which are started and operated on two capacitors with identical windings), the main and auxiliary windings are connected incorrectly. The current is much higher than the rated value.
• The operating capacitor is damaged or the wrong capacitance is used.
• The stator and rotor cores are rubbing against each other or the bearings are damaged. The sound is abnormal and the current is higher than the rated value.
• Heavy load. The current is higher than the rated value.
• In the case of series-excited motors, a short circuit between the commutator plates or inside the armature winding, or poor contact between the brushes and the commutator.

Compared with the same capacity or the same number of seats of three-phase induction motor, single-phase motor noise and vibration (especially vibration) is relatively large. This is because its rotating stator magnetic field is not a regular circle, so the torque will not always be the same, that is, there will be fluctuations in the size of a circle, resulting in radial vibration of the rotor. The most common causes of high noise and vibration are
• Poor paint impregnation, resulting in looseness between the cores, generating higher frequency electromagnetic noise.
• Damaged centrifugal switch.
• Damaged bearings or excessive axial clearance.
• Uneven air gap or axial misalignment between stator and rotor.
• Foreign matter inside the motor.
• In series-excited motors, a short circuit between the commutator plates or a short circuit inside the armature winding, or poor contact between the brushes and the commutator (mica between the commutator plates higher than the commutator plates, or rough commutator plates, or brushes too hard, too much pressure, etc.).