（1） Determination conditions for elevator maintenance

1. Except for a few components that do not need to be disassembled, they need to be cleaned, lubricated, and the bolts of the electrical terminals that exceed the distance of the upper and lower terminals need to be disassembled and inspected.

2. It is necessary to dismantle the transmission components and mechanical and electrical safety devices of the elevator. Parts with abnormal noise or wear need to be replaced, and some electrical components need to be disassembled and repaired

3. Newly installed elevators that have been in use for more than 2 years and are frequently used.

4. Any item that meets any of the three criteria (1), (2), or (3) above can be considered as a medium repair project.

（2） Elevator maintenance project content

A、 Intermediate repair content of mechanical components of elevators

1. Clean the worm gear gearbox of the traction machine and replace the gear oil inside the gearbox.

2. Replace the asbestos packing or oil resistant rubber sealing ring at the extension of the traction machine worm shaft.

3. Replace the sealing ring between the worm gear reducer cover and the box body of the traction machine or reapply sealant.

4. Replace the asbestos brake band of the brake shoe and adjust the gap between the brake shoe and the brake wheel to be less than or equal to 0.7mm And make the gap uniform.

5. Adjust the linkage part of the elevator door, replace the pulley of the elevator door, and replace the lower sliding block of the door leaf.

6. Adjust the spring compression force of the electromagnetic brake.

7. Adjustment or replacement of the rope pressure block on the speed limiter.

8. Adjust the gap between the car safety clamp wedge and the guide rail to 2-3mm, and keep the gap uniform and consistent

9. Check and adjust the connection between the wire rope of the speed limiter and the connecting rod of the safety gear, and check the tension and elongation of the speed limiter.

10. Adjust and replace the guide shoes and shoe linings of the elevator car and counterweight.

11. Check and adjust the tension of the traction steel wire rope.

12. Check and adjust the meshing condition of the door knife and the mechanical hook lock of the layer door.

13. File the scratches on the guide rail and recalibrate the guide rail.

B、 Content of Electrical Maintenance Projects

1. Check and tighten the wiring bolts on each contactor and relay.

2. Check and adjust the reliability and position of each limit switch in the wellbore.

3. Check and replace the reliability of the operation of each magnetic switch in the wellbore.

4. Check and replace the button components, switches, and electrical components on the car control box and the call button boxes outside each floor hall.

5. Measurement and processing of insulation resistance for power circuits and signal lighting circuits.

6. Check and adjust the reliability of door protection, photoelectric protector, and overload/full load operation.

7. Check and replace the rotary encoder.

8. Check the elevator's starting and braking comfort and leveling accuracy.

If 60-70% of the above projects require inspection, replacement, and adjustment, it can be considered as the intermediate repair level of the elevator.

（3） The content of the elevator overhaul project

A、 Determination of Elevator Overhaul Project

1. Elevators that have been repaired twice or more;

Although the elevator has not been repaired, it has been in use for 3-5 years.

3. The elevator has experienced a major accident and its main components have been severely damaged.

B. The content of the mechanical component overhaul project for elevators

1. Disassembly and repair of worm gear reducer.

2. Adjust and scrape the backlash between the worm gear teeth.

3. Adjust and replace the bearings and asbestos gaskets or rubber seals on the extended end of the worm shaft.

4. Replace the rear door head flat bearing of the worm shaft.

If the casing and cover castings of the worm gear reducer have severe deformation or cracks, they should be replaced or repaired.

6. Disassembly and repair of electromagnetic brake. Clean and replace brake pads, adjust clearances.

If there is abnormal friction sound in the traction motor, significant increase in starting and braking current, increase in axial displacement, and increase in no-load current, the motor of the same model and specification should be replaced.

8. Disassemble and repair the speed limiter, set the operating speed, and seal it.

9. Clean the wire rope of the speed limiter, cut off the extended part, and inspect and lubricate the transmission part of the tensioning wheel.

10. Replace the wedge block of the safety clamp and adjust the gap between it and the guide rail surface evenly, keeping the gap within 2-3mm. And test the reliability of the safety clamp action with the maintenance speed.

11. Clean the guide rails, replace severely deformed car guide rails, or adjust their verticality and parallelism by adding guide rail brackets.

12. Shaping and replacing severely deformed car walls.

13. Disassemble and repair the automatic door machine or replace it with a complete automatic door machine of the same model and size, or replace the door motor.

14. Repair or replace the interior decoration of the car.

15. Adjust the linkage of the elevator door, check and replace the elevator door pulley, and replace the severely deformed elevator door leaf.

16. Replace or re turn the rope grooves of the guide wheel and traction wheel, remove and wash their axles, replace and lubricate the bearings.

17. Thoroughly inspect and clean the oil pressure buffer, and replace the buffer oil.

18. Check the reliability of the full load and overload device operation of the elevator car.

19. Painting of the elevator car and landing doors.

20. Adjust and replace the car, counterweight guide shoes, and their shoe linings.

21. Shorten and elongate the traction steel wire rope or replace the severely broken traction steel wire rope.

C、 Overhaul project for the electrical part of the elevator

1. Replace the relays, contactors or rewire the control screen.

2. Due to the addition of elevator control functions, the control screen has been replaced.

3. Adjust and replace the door lock nodes or switches of individual floors.

4. Adjust the action position of each limit protection switch in the shaft and replace the individual switch components.

5. Organize the components and layout lines in the control boxes and button boxes of each floor inside and outside the car.

6. Replace the wires (including power lines) inside the conduit (slot).

7. Check the insulation resistance of power lines, signal lines, and lighting circuits.

8. Check and replace the broken strands or aging cables of the accompanying cables.

9. Check and replace the functions and components of the signal indication system.

10. Check and replace the moving and stationary contacts of the magnetic switch inside the shaft.

11. Check and adjust the main power switch and fuse with severe erosion.

12. Check and adjust the overall performance of the elevator to meet the original design requirements.

13. Check and adjust the various functions of the elevator to meet the original design requirements.

If 60-70% of the above items need to be inspected, replaced, or adjusted, it can be considered as a major overhaul of the elevator.

D、 The "Service Standards for Minor Repairs of Buildings and Their Equipment" document Jingfangdi Xiuzi [1998] No. 799 has been implemented since September 1998. This standard specifies the minor repair content, quality standards, and service time limits for houses and their equipment. The following is an excerpt of the residential elevator minor repair service standards: