WHY DO WE NEED AUTOMATIC RESCUE
DEVICE FOR ELEVATOR?
Elevator Automatic Rescue Device ARD (such as:
SOJI SJ-60VDC) is applied to emergency running when the electric grid is in an abnormal state. When elevator stops between floors due to power failure, the ARD can supply power to allow the elevator to slowly land on the nearest floor and enable the door of the elevator to be opened automatically with the battery provided in ARD, so as to let the passengers out safely. Through the coordination of the internal control circuit with transducer and microcomputer board, the ARD achieves automatic leveling function of elevators during power failure. Compared with similar traditional products, the ARD has the advantages of maximum utilization of the original resources of the control system, low price, high reliability and controlling flexibility.
The ARD can be applied to the variable voltage & variable frequency elevator (VVVF elevator) driven by gearless permanent magnet synchronous motor or asynchronous motor.
During operation, the ARD supplies power and controlling signals to the transducer and the microcomputer board via the internal controlling circuit. The internal control unit, transducer and microcomputer board coordinate the elevator to move slowly and level onto the nearest floor and open the door. The detailed functions are as follows:
1. The our ARD and the control system are electric interlocked reliably. When power is restored, the elevator runs normally.
2. The ARD runs only when all the following conditions are met:
① Power supply is failed for elevator.
② Elevator is not in the maintenance state.
③ Elevator is not in the door zone.
④ The signals of elevator safety circuit and door interlock circuit are normal.
3. If only ③ of the above conditions is not met while all the other conditions are met, the door of the elevator can be opened automatically by the ARD.
4. If the elevator is equipped with a load weighing device, in emergency the elevator runs in the direction which is determined by the loading condition.
5. The leveling is accurate, and the accuracy is up to ±15mm.
6. The ARD offers a maximum running time protection function
(usually for 2 min).
7. The ARD offers an automatic constant voltage and constant
current charging function
