Three-phase AC servo motors are widely used in industrial applications due to their high precision and efficiency. However, after prolonged operation, various faults may occur. Identifying the root cause of these issues promptly and taking corrective actions is crucial to prevent further damage and ensure the equipment operates smoothly.
1. After power is turned on, the motor cannot rotate, but there is no abnormal noise, smell, or smoke.
Causes: 1. Power supply not properly connected (at least two phases missing). 2. Blown fuses (at least two blown). 3. Overcurrent relay set too low. 4. Wiring errors in control devices.
Solutions: 1. Check the power switch and fuses for breaks; repair as needed. 2. Inspect the fuse type and replace it if necessary. 3. Adjust the relay setting to match the motor’s requirements. 4. Correct the wiring connections.
2. Motor does not turn after power is applied.
Causes: 1. Rotor winding open circuit (one phase disconnected) or phase imbalance. 2. Winding lead wires connected incorrectly or internal winding reversed. 3. Loose contacts in the power circuit with high resistance. 4. Excessive load or rotor jammed. 5. Low power supply voltage. 6. Tight assembly of small motors or hard grease in bearings. 7. Bearing seizure.
Solutions: 1. Locate and repair the open circuit. 2. Check the winding polarity and confirm the terminal connections. 3. Tighten loose screws and use a multimeter to check for false connections. 4. Reduce the load or fix mechanical issues. 5. Verify the correct connection method and check for excessive voltage drop. 6. Reassemble and replace the bearing grease with a suitable product. 7. Repair or replace the bearing.
3. Motor starts with difficulty, and speed is lower than rated under full load.
Causes: 1. Low power supply voltage. 2. Incorrect connection of the motor. 3. Open or broken rotor winding. 4. Local coil misconnection or reversal. 5. Excessive number of windings. 6. Motor overload.
Solutions: 1. Measure the voltage and try to increase it. 2. Correct the connection method. 3. Check for open circuits and repair. 4. Identify and fix misconnections. 5. Restore the correct number of turns. 6. Reduce the load.
4. Unbalanced no-load current with large three-phase differences.
Causes: 1. Incorrect winding terminal connections. 2. Unbalanced power supply voltage. 3. Faults in the winding such as inter-turn short circuits or coil reversal.
Solutions: 1. Check and correct the winding connections. 2. Measure and balance the power supply voltage. 3. Eliminate any winding faults.
5. Abnormal noise during motor operation.
Causes: 1. Worn bearings or foreign objects in the lubricant. 2. Loose rotor core. 3. Lack of lubrication in bearings. 4. High or unbalanced power supply voltage.
Solutions: 1. Replace the bearing or clean it thoroughly. 2. Repair the rotor core. 3. Add proper lubrication. 4. Check and adjust the power supply voltage.
6. Excessive vibration during motor operation.
Causes: 1. Excessive bearing clearance. 2. Uneven air gap. 3. Rotor imbalance. 4. Shaft bending. 5. Poor alignment between coupling and pulley.
Solutions: 1. Repair or replace the bearing. 2. Adjust the air gap to be uniform. 3. Balance the rotor dynamically. 4. Straighten the shaft. 5. Recalibrate the coupling to meet standards.
7. Bearings overheating.
Causes: 1. Excessive or insufficient grease. 2. Poor quality grease with impurities. 3. Misaligned bearing with journal or end cap. 4. Eccentric bearing causing friction. 5. Non-flat end caps or bearing covers. 6. Poor alignment between motor and load or tight belt. 7. Incorrect bearing clearance. 8. Bent motor shaft.
Solutions: 1. Add grease according to specifications (1/3–2/3 of volume). 2. Replace with clean, high-quality grease. 3. Repair by adjusting fit or grinding. 4. Fix the bearing cover to eliminate rubbing. 5. Reassemble properly. 6. Recalibrate and adjust belt tension. 7. Replace the bearing. 8. Straighten the shaft or replace the rotor.
8. Motor overheats and emits smoke.
Causes: 1. High power supply voltage. 2. Low power supply voltage causing high current and overheating. 3. Improper thermal disassembly during winding repairs leading to core damage. 4. Overloading or frequent starting. 5. Phase loss leading to two-phase operation. 6. Inadequate insulation coating after rewinding. 7. High ambient temperature, dirty motor surface, or blocked air ducts.
Solutions: 1. Lower the voltage by adjusting the transformer tap. 2. Increase the voltage or use thicker wires. 3. Repair the core to eliminate damage. 4. Reduce the load and limit start frequency. 5. Restore three-phase operation. 6. Use secondary dipping paint and vacuum process. 7. Clean the motor, improve ventilation, and implement cooling measures.
Inspection Lifting Column,Motorized Lifting Column,Single Column Car Lift,Telescopic Pneumatic Cylinder
Kunshan Zeitech Mechanical & Electrical Technology Co., Ltd , https://www.zeithe.com