Simple 7 steps for Motor maintenance

The motor is one of the indispensable equipment in production and manufacturing. In order to ensure the normal operation of the motor, in addition to normal use according to the operating procedures and normal monitoring and maintenance during operation, regular inspections should be carried out to maintain the motor.

1. Check:

a. Check and clean the motor terminals. Check whether the wiring screws of the junction box are loose or burnt.

b. Check the screws of each fixed part, including anchor screws, end cover screws, bearing cover screws, etc. Tighten any loose nuts.

c. Check the transmission device, check whether the pulley or coupling is strong, damaged, and whether the installation is firm; whether the belt and its coupling buckle are intact.

d. Check whether there are burn marks on each wiring part and whether the grounding wire is in good condition.

2. Look: Look at the magnitude and change of the working current of the motor, and see if there is any water leakage or dripping around, which will cause low breakdown of the motor insulation and burn it out. It also depends on whether there are objects around the motor that affect its ventilation and heat dissipation environment? Check whether the fan cover, fan blades and the outside of the motor are too dirty and need to be cleaned? To ensure its cooling effect.

3. Listening: Listen carefully to see if the sound of the motor is running normally. If the environment is noisy, you can use auxiliary tools such as a screwdriver or a listening stick to listen to both ends of the motor. If there is any abnormal sound, deal with it in time.

4. Touch: Use the back of your hand to detect the temperature around the motor. In the case of good bearing condition, the temperature at both ends is generally lower than that of the middle winding section. If the temperature at both ends of the bearing is high, it is necessary to check the bearing in combination with the measured bearing sound. If the overall temperature of the motor is high, it is necessary to check the load, equipment and ventilation of the motor in combination with the working current and deal with it accordingly.

According to the insulation grade of the insulating material used in the motor, the limit temperature at which the winding insulation can be used for a long time when the motor is running can be determined, or the allowable temperature rise of the motor (the actual temperature of the motor minus the ambient temperature). There are differences in the insulation grade standards of various countries, but they are basically divided into: Y, A, E, B, F, H, and C. Among them, the allowable temperature rise of Y grade (45°C) and the allowable temperature rise of C grade ( above 135°C). Considering the bearing oil and other materials, the temperature measured with a thermometer close to the motor should be controlled below 85°C.

5. Measurement:

a. When the motor stops running, regularly use an insulation meter to measure the insulation resistance of each phase to ground or phase to phase. In wet weather and winter, special attention should be paid to the waterproof, moisture-proof and drying of the motor. If it is found that the motor is soaked in water, just disassemble the motor and pull out the rotor, rinse it repeatedly with hot fresh water at 60-70°C, dry it with compressed air, and then bake it from both ends of the motor stator with a baking lamp until the insulation of the motor rises to normal.

b. When the motor is running, measure its working voltage and current, the voltage should be equal, and the current imbalance of each phase should not exceed 10%. If the current difference of each phase measured by the clamp meter is too large, there may be an inter-turn short circuit.

6. Lubrication: Ensure good lubrication of the motor during operation. Generally, the motor runs for about 5000 hours, that is, the grease should be replenished or replaced. When the bearing is found to be overheated or the lubrication has deteriorated during operation, the hydraulic pressure should replace the grease in time. When replacing the grease, the old lubricating oil should be removed, and the oil groove of the bearing and bearing cap should be cleaned with gasoline.

7. Keep the motor clean: During the operation of the motor, dust, water stains and other sundries are not allowed within at least 3 meters around the air inlet, so as to prevent it from being sucked into the inside of the motor, forming a short-circuit medium, or damaging the wire insulation layer, causing a gap between the boxes. Short circuit, the current increases, the temperature rises and burns the motor. Therefore, it is necessary to ensure that the motor has sufficient insulation resistance and a good ventilation and cooling environment, so that the motor can maintain a long-term safe and stable operating state.

To sum up, as long as the motor is routinely maintained and inspected according to the above, the failure rate of the motor will be greatly reduced, and the service life of the motor will be extended, thereby saving a considerable amount of maintenance costs and the cost of purchasing a new motor.

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