Single-phase induction motor used are: capacitor run, capacitor start, capacitor start, capacitor run, resistance (phase) to start the four, as shown in the schematic in Figure 1,2,3,4. Capacitance can cause damage to the motor does not start, run, weakness, burning Vice burn group and other failures.
I talk about examples no mechanical failure in the motor context. Capacitor failure caused damage to repair.

Example 1: Wuhan production XXD-120 washing machine motor. Humming not to switch.
The machine is single-phase 4-pole motor running capacitor, capacitor and secondary winding and primary winding in series and then parallel access circuit, shown in Figure 1. Does not turn the motor hums, it may be a bad run capacitor, group vice burn open or short circuit. First remove the capacitor, R × 1k block with a multimeter test and found no longer charge-discharge capacity. R × 1 block with a multimeter test the motor leads to the three wires, red and blue line of resistance to 27n, the yellow line and blue line resistance to 27n, red and yellow lines resistance to 54n, that the main and secondary windings is good. For CBB60 Capacitor 1ouF, failure in addition.

Example 2: Shanxi production C02-90L ~ 2 1.5HP motor, and the supporting power planer woodworking,
Does not turn the motor humming.
This machine is a single-phase capacitor start asynchronous motor, capacitor and secondary winding, centrifugal switch in series, and then access and main winding parallel circuit shown in Figure 2. According to the principle of single-phase capacitor start motor hums may not turn a bad capacitor, short circuit or open circuit secondary winding, centrifugal switch is open cause. Switch set to the middle of the inverted position, remove the start capacitor. R ~ I use the multimeter test block a main winding U1 u2 resistance to normal. Secondary winding Wl-W2 in the motor shell and centrifugal switch in series resistance of the normal, shown in Figure 5. Measured by R ~ 100 block capacitor Biaozhen fretting, that capacitance is not enough, for CD60 Capacitor 200, trouble shooting.

Example 3: Zhengzhou production Y90L-2 3kW motor, and the supporting feed mill, power load is operating normally, the feeding to stop.
This motor is capacitor start capacitor run induction motor. Principle shown in Figure 3, terminal block connection shown in Figure 6. Remove W2U1 and U2V1 connecting piece, open from unloading Wl terminal run capacitor start capacitor and the lead, measured with a multimeter ohm U1 a U2 block the main winding and secondary winding resistance Wl-w2 normal, V1V2 from a Ii, Switch On , the measured normal start capacitor C, is no longer running capacitor C charging and discharging capacity, the replacement of CBB60 type 40b [F capacitor operation, troubleshooting.
Example 4: Shenzhen production E0-90L1-4 1.1kW motor, matching wood planer. Power noise, dynamic, high fever a few minutes motors, power-off hot and then burst. This machine wiring shown in Figure 6. Switch to set down the inverted position, remove the start capacitor and running capacitors. Measuring a primary winding U1 U2, secondary winding resistance of normal Wl-W2, then columns VIV2 zero centrifugal switch, the measured c capacitors functioning well. Replacement of 150 /. LF capacitance test, fault remains. Suspect that there is no separation centrifugal switch, start capacitor in series with secondary winding run, causing a large electrical current is high fever. Re-test machine, the motor
Shutdown hear centrifugal switch “Kacha” closed sound, determined from the Ii, switch can not be separated. Disassemble centrifugal switch contacts observed bond. Centrifugal switch replacement and 150 /. LF start capacitor, troubleshooting.
Example 5: Shanghai production Y90L-2 2.2KW motor, supporting corn sheller. Light load to operate the load is down a little, weak. Figure 6 wiring, remove the wiring connector board two films, measured with a multimeter power block a main winding U1 u2, secondary winding Wl-W2, resistance was normal, the centrifugal switch pass, start capacitor is good, but test run capacitor c time, hands swing is very small, then capacitance meter measured capacity is only s F, that capacitance decreases. Replacement CBB60 type 30 /. LF capacitance running after troubleshooting. Example 6: Shanghai production YL100-2 3KW motor and supporting the nuclear option apricot peeling machine, it’ll power the motor, security clamor immediately trip. The owner said that the security operation in the trip the short access the user security device, security device and trip meter box. Maintenance department, said motor connected Rail Line package, need-for-line package. Because there is no smell of burnt smell in use have not seen smoke, do not believe that the motor will burn. Specially sent for inspection. Posts with the shake table test on the chassis insulation resistance ON. Apricot election because of work in the wet apricot kernel machine processing, water great, easy to damp. Poor motor damp insulation is common. Sealing-off but can not rule out the centrifugal switch chassis, or from the collision thread, t2, switch spring
Iron due to take off and other failures, this teardown. Good observation centrifugal switch, main, secondary winding wire packages are not burning the black color phenomenon, and no signs of damp water. Measured in the terminal board and then still take iron. Determine the access of iron parts, dismantling W2U2, U1VI connecting piece,
A good test ground U1, W2 is zero on the chassis, remove the C from the W2 to the case of zero capacitance. Remove the capacitor C, W2, vice around the group of normal. Is running capacitor connected iron? Then be a simple box out run capacitor capacitance observed. Lead screw terminal capacitor is bursting, just stand up capacitor lead wires, screws, brackets connected through a capacitor case. Good measure capacitance, the capacitor pad lining with lead wire end well, and use short screws after troubleshooting.