Three-phase asynchronous motors are widely used power output equipment in domestic equipment. The quality of the motor is often related to whether the equipment can run forever. In recent years, the manufacturing process of the motor manufacturer is thick and the quality of the motor is uneven. Keep your eyes open when buying!
1. Listen to the sound of three-phase asynchronous motor running
Let the motor run for 15-25 minutes with the power on and listen to the sound of the motor running. The sound of the motor running after power-on should be smooth, brisk and free of stagnation. The sound is well-balanced and balanced. Everyone can hear the fine "humming" electromagnetic noise and the fine "sandy" machine noise. If it presents harsh, dull, friction, vibration and other unpleasant noises, it means that the quality of the motor is not good.
2. Let the motor run for a period of time. After the operation is contained, touch the motor seat and end cover by hand. The motor seat and end cover should not feel feverish, and the bearing temperature is not high; check carefully, there should be no oil leakage or oil rejection. .
3. Open the junction box and check the wiring. The end symbols of each phase line of the high-quality motor are clear and complete. The connecting pieces have been compacted, the nuts are complete, and there are grounding bolts.
4. Measure the insulation resistance and current of the three-phase asynchronous motor, use a megohmmeter with a rated voltage of 500V to measure the insulation resistance between the phase line and the phase line and between the phase line and the base at the outlet end, and the insulation resistance of the qualified motor More than 0.5 megohm. When the motor is running, use a clamp ammeter to measure the current of each phase when the motor is no-load. The error of any one phase and the average value of the three-phase current shall not exceed 10% of the average value. The no-load current should be 25 of the rated current. %-50%.
To choose a motor manufacturer, you must choose a motor manufacturer with strength and good promise. This not only guarantees the quality of the three-phase asynchronous motor, but also provides better protection for after-sales consultation.