China Escalator Factory introduces elevator maintenance knowledge:

1. The phase sequence of the input power supply is wrong or there is a phase loss, which causes the phase sequence relay to act.
2. The elevator is in overload operation or locked rotor for a long time, causing the thermal relay to act.
3. It is possible that the Overspeed of the speed limiter may cause the speed limiter switch to act.
4. The limit switch action is caused by the elevator reaching the top or sinking to the bottom.
5. Pit broken rope switch action. Possibly the speed limiter rope jumped out or was too long.
6. Safety gear action. The reasons should be found out, which may be the Overspeed action of the speed limiter, the malfunction of the speed limiter due to oil loss, the oil loss of the pit sheave, the involvement of foreign objects (such as mice, etc.) in the pit sheave, and the small gap of the safety block.   
7. The safety window is jacked up, causing the safety window to switch.
8. Some emergency stop switches may be pressed.
9. If all switches are normal, check whether their contacts are in good contact and whether the wiring is loose.

Through the above introduction, Automobile Elevator Factory hopes that you can simply refer to the content of this article for future use.