Common faults and causes of single-phase capacitors to start asynchronous motors - News - Global IC Trade Starts Here.

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Single-phase motors are typically categorized based on their starting methods or operational modes. These include single-phase resistor-start, single-phase capacitor-start, single-phase capacitor-run, single-phase capacitor-start-and-run, and single-phase shaded-pole types. Among these, the single-phase capacitor-start and run asynchronous motor is the most commonly used in various applications.

In rural areas, where power supply quality may be unstable and grid usage is not always optimal, single-phase motors tend to experience higher failure rates. Common issues include excessive motor heating, poor rotation, difficulty in starting, and blown fuses. Below are some of the typical faults and their possible causes in single-phase capacitor-start asynchronous motors:

Fault 1: The motor does not start even when the power is turned on. Possible reasons: 1. A broken motor lead; 2. Open circuit in the main or auxiliary winding; 3. Centrifugal switch contacts not closing properly; 4. Faulty or open capacitor; 5. Stuck bearings; 6. Rotor and stator rubbing against each other.

Fault 2: The motor can start under no load or with external assistance, but it starts slowly and runs unevenly. Causes may include: 1. Open auxiliary winding; 2. Poor contact from centrifugal switch; 3. Damaged or open starting capacitor.

Fault 3: The motor heats up quickly or even burns out after starting. This could be due to: 1. Short circuit or grounding in the main winding; 2. Short between main and auxiliary windings; 3. Centrifugal switch fails to open after starting; 4. Incorrect wiring of main and auxiliary windings; 5. Friction between rotor and stator.

Fault 4: Low speed and weak operation. Possible causes: 1. Minor short circuit in main winding turns; 2. Open or reduced capacity running capacitor; 3. Bearings too tight; 4. Low power supply voltage.

Fault 5: Blown fuse. This may occur because: 1. Severe short circuit or grounding in the winding; 2. Grounded or shorted lead wire; 3. Capacitor breakdown and short circuit.

Fault 6: Excessive noise during operation. Reasons might be: 1. Winding leakage; 2. Damaged centrifugal switch; 3. Worn bearings or excessive gap; 4. Foreign objects inside the motor.