Analysis on the working principle of elevator emergency device
Posted by Admin | 25 Oct
Elevator energy-saving equipment suppliers remind you: In today's city full of high-rise buildings, elevators are an indispensable tool in office or residential areas. However, the elevator needs frequent maintenance to maintain the normal and safe operation of the elevator.
Elevator maintenance is mainly to maintain its normal operation. If the elevator has an emergency situation, such as power outages, fires and other emergencies, it needs elevator emergency devices to handle it.
The working principle of elevator emergency device
Power detection When the external power grid is normally powered, the power detection circuit of the emergency device gives a normal signal of AC input power, and the battery pack of the device is automatically floated through the charging circuit to maintain the rated operating voltage. The charging circuit has protection functions such as overcharge and discharge, overcurrent and short circuit.
Emergency operation When the elevator suddenly encounters a power failure and the elevator control system stops running, the DSP control system of the emergency device will immediately detect the elevator status and automatically engage in emergency rescue. First, K1A pulls in, cuts off the power supply from the external grid to the elevator control transformer, and performs electrical interlocking. Then check the elevator safety, door locks and maintenance circuits, and supply power to the door zone sensor, detect the leveling signal, and if it is normal, start the current converter to supply power to the door machine control system (AC door machine, DC door machine, variable frequency door machine) , The door opening motor MD obtains the required voltage and opens the car door and hall door at the same time; if the car is not in the leveling position, the relay normally open contact is closed, and the DC converter supplies power to the brake circuit to open the brake, three-phase The voltage output by the inverter circuit supplies power to the traction machine through the normally open contact of K2A, and the traction car runs in a certain direction. The car runs to the leveling position and stops. Stop the output of the three-phase inverter voltage and close the brake. After the car door and hall door are opened, the contacts of the above-mentioned contactors of the emergency device and the contacts of the relay are all restored to the state before the emergency operation.
Safety lockout If the DSP control system of the emergency device judges that the stop of the elevator is a failure of the safety circuit or the door lock circuit, the device will not be put into emergency operation according to the requirements of the elevator operation "Safety Regulations". Even after the emergency device is put into emergency operation, it is always monitoring the signals of the elevator safety circuit and the door lock circuit. Once any protection signal is generated, the emergency operation will be terminated immediately to ensure the safety and reliability of passengers and elevator equipment. Similarly, the emergency device is always monitoring the overhaul circuit of the elevator control system. When the maintenance personnel inspect the elevator, as long as the inspection switch is pressed, the device will be automatically locked and not put into emergency operation.
Emergency end After the emergency operation is over, the device is disconnected from each part of the elevator control system, and is in an isolated standby state, which has no effect on the normal operation of the elevator. When the three-phase AC power supply is restored, the charging circuit of the emergency device will automatically recharge the battery pack.
Install multiple "safety belts" for elevators. Many developers and property management departments have always lacked the necessary investment and attention to the reliable power supply of elevators. Due to power shortages, some lines in the main urban area will still have emergency local short-term power restrictions. In addition, various external damages may also cause local power outages. If the elevator is equipped with emergency power supply, in the event of an emergency power failure, the normal operation of the elevator can be guaranteed to facilitate the safe transfer of passengers.