In order to facilitate maintenance and maintenance, should be installed in the car roof is easy to close the control device. The device shall have an overhaul operation switch that meets the electrical safety requirements. The switch should be bistable and free to operate with unintentional protection. The following conditions should also be met:
Once the maintenance operation, should cancel the normal operation, emergency operation of the electric state, docking loading and unloading operation. Only once again operation maintenance switch, in order to make the elevator back to normal work. Up and down can only jog operation, in order to prevent accidents, should indicate the direction of operation. Car maintenance speed should not exceed 0.63m / s, the elevator operation should still rely on safety devices, running can not exceed the normal range of operation.
Generally have the following protection links: Overspeed protection switch, floor lock device electrical interlock protection, door entrance security protection, the upper and lower end of the station beyond protection, phase failure, phase protection, elevator control system in the short circuit protection, Traction motor overload protection.