Maintenance of Explosion-Proof Motors

1. For the motor’s starting equipment, promptly remove external dust and dirt, wipe down the contacts, check all wiring connections for signs of burning, and ensure the ground wire is secure.

2. Inspect and clean the motor’s terminal blocks. Check whether the wiring screws in the junction box are loose.

3. Inspect all fasteners and tighten any loose nuts.

4. Clean the motor. Promptly remove dust and oil stains from the exterior of the motor frame. If the operating environment is dusty, clean it once a day.

5. The insulating capacity of insulating materials varies depending on their dryness, so it is crucial to check the dryness of the motor windings. Factors such as a humid operating environment or the presence of corrosive gases in the workspace can damage the motor’s insulation. A common issue is a ground fault in the windings, which occurs when insulation failure causes live parts to come into contact with non-live metal components such as the motor housing. Such faults not only impair normal motor operation but also pose a safety hazard. Therefore, during operation, regularly check the insulation resistance and ensure the motor housing is properly grounded.

6. Inspect the drive system: Check the pulleys or couplings for cracks or damage, and ensure they are securely installed; verify that the belts and their fasteners are intact.

7. Maintenance of motor carbon brushes: During motor operation, carbon brush wear is a major factor leading to motor failure. Therefore, attention must be paid to the maintenance of carbon brushes during use, which means regularly replacing them with new ones to ensure smoother operation.

8. Bearing inspection and maintenance. Bearings should be cleaned and have their grease or oil replaced after a period of use. The frequency of cleaning and oil changes depends on the motor’s operating conditions, environment, cleanliness, and type of lubricant. Generally, cleaning and re-greasing should be performed every 3–6 months. Motors operating in high-temperature environments, poor conditions, or dusty environments require more frequent cleaning and oil changes.

9. During motor operation, a common issue is the motor emitting unusual noises, primarily caused by the cooling fan. If dust on the cooling fan is not cleaned promptly, it can lead to abnormal operation. Therefore, ensure the cooling fan remains clean during use.

10. To prevent rust on the explosion-proof surfaces, apply machine oil or 204-1 displacement-type rust-preventive oil to these surfaces.

11. When disassembling the motor, first remove the fan shroud and fan. Then, use a socket wrench to loosen the bolts securing the end cover and bearing cover. Next, tap the shaft extension axially with a round wooden block or copper rod to separate the end cover from the frame, and remove the rotor. When removing parts, place the explosion-proof surfaces facing upward and cover them with rubber or cloth padding. Take care not to lose fastening bolts, spring washers, or other small parts.

12. During varnishing and assembly, thoroughly clean any insulating varnish or dirt adhering to the explosion-proof surfaces. Do not scrape them with hard objects such as metal sheets, but uneven areas may be smoothed with an emery stone.