I. Appearance inspection:
1. Check whether the motor housing has cracks, open welding, deformation, whether the spare parts are complete, and whether there are any damages.
2. Check whether the fasteners of the explosion-proof parts are complete, and whether the fastening screws and holes have any slip buckles.
II. Rotor inspection:
After pulling out the rotor, remove the inner and outer small covers to check whether there is any damage. The rotor squirrel cage bars and end rings are welded firmly and reliably, and there shall be no open welding or false welding.
III. Bearing inspection:
Remove the backrest wheel to check whether there is any damage, remove the bearing to check whether there are any cracks, peeling, pitting, discoloration and rust spots
IV. Stator inspection:
1. The stator core and winding surface are clean, and the winding is insulated. There should be no obvious damage and changes.
2. When the winding is fully rewound, the insulation level, winding pitch, wire cross-section, etc. should be the same as the original design.
3. Number of immersions: immersion is not less than 3 times.
V. Cooling system:
Check that the water channel of the water-cooled motor is unobstructed, the seal is intact, there is no leakage, and a good water pressure test is performed.
6. Explosion-proof surface inspection:
The repair of each explosion-proof part of the explosion-proof motor complies with the GB3836.2-2000 standard.
7. Test:
1. Insulation resistance value of winding: should be lower than 5MΩ (660V, 380V), 1140V not less than 10MΩ.
2. Withstand voltage test: 380V-2000v/min, 660V-2500v/min, 1140V-3000v/min.
3. No-load test: The unbalanced value of the three-phase no-load current does not exceed 10%, and the operation is stable without abnormal noise.
 
When repairing explosion-proof motors, special attention should be paid to the following.


matters:
1. Safety first: There is a certain risk of fire and explosion when the explosion-proof motor is running, so the safety of personnel must be ensured during maintenance. Workers should wear personal protective equipment that meets safety requirements, such as protective clothing, safety helmets, protective glasses, etc. At the same time, the working area needs to be isolated to ensure that there are no flammable and explosive items around, and special explosion-proof tools and equipment are used for maintenance.
 
2. Understand the structure and working principle of the motor: Before repairing the explosion-proof motor, you need to understand the structure and working principle of the motor. Be familiar with the various components of the motor and their functions, and conduct targeted inspections and repairs on the faults and points in it.
 
3. Regular inspection and maintenance: The explosion-proof motor will be affected by large loads and the environment during operation, so it needs to be inspected and maintained regularly. Clean the dust on the surface of the motor regularly, check whether the wiring of the motor is loose, check whether the bearings of the motor are well lubricated, etc. If a fault or abnormality is found, it should be repaired or replaced in time.
 
4. Check the power supply and power supply system of the explosion-proof motor: Before repairing the explosion-proof motor, it is necessary to check the normal operation of the power supply and power supply system. Ensure the stability of the power supply voltage and frequency, check whether the cable is damaged or aged, and ensure that the cable connector is firmly and reliably connected:
 
5. Strictly follow the maintenance process: When repairing the explosion-proof motor, it is necessary to follow a certain process and follow the corresponding operating procedures. First, the power supply needs to be cut off, and then the motor needs to be inspected and repaired. After the inspection and repair are completed, a trial run can be carried out. During the operation, it is necessary to strictly follow the operating procedures to ensure the accuracy and safety of each step.
 
6. Check the insulation condition of the motor: The insulation condition of the explosion-proof motor is crucial to its safe operation. During the inspection, the insulation condition of the motor needs to be checked, and the insulation material is tested by the insulation resistance star meter to ensure that its insulation condition meets the requirements. If the insulation material is found to be aging, damaged or the insulation resistance is too low, it should be replaced in time.
 
7. Reasonable selection of lubricating materials: When inspecting the bearings of explosion-proof motors, it is necessary to select lubricating materials that meet the requirements. The selection of lubricating materials should be in accordance with the use environment and working conditions of the motor. At the same time, avoid using flammable and explosive lubricating materials to ensure the safe operation of the motor.
 
8. Check the grounding system of the motor: The grounding system of the moisture-proof motor is an important part of preventing static electricity accumulation and leakage in the motor. During maintenance, it is necessary to check whether the grounding system of the motor is normal, ensure that the grounding resistance meets the requirements, and avoid safety accidents caused by poor grounding.
 
9. Pay attention to the protection level of the explosion-proof motor: The protection level of the explosion-proof motor has an important impact on its safety. During maintenance, it is necessary to understand the protection level of the motor and operate according to the requirements. It is particularly important to note that the shell of the explosion-proof motor cannot be disassembled at will to prevent the destruction of the explosion-proof structure
 
10. Keep maintenance records: After the explosion-proof motor is repaired, a complete maintenance record should be kept. The record should include the basic information of the motor, inspection results, maintenance measures, and the signature of the maintenance personnel. These records can be used as a basis for judging the operation of the motor and problem solutions in the future.
 
In short, when inspecting explosion-proof motors, safety comes first, and special attention should be paid to personnel safety, and operations should be carried out in accordance with the operating procedures. Check the insulation condition of the motor, the grounding system, and the selection of lubricating materials, etc., record the inspection process and results, and ensure the safe operation of the motor. At the same time, regularly inspect and maintain the explosion-proof motor, find and eliminate faults in time, and ensure the normal operation of the motor.