Engineered with smart safety architectures and built for high-performance operations across residential, commercial, and industrial scenarios.
An in-depth analysis of vertical safety technologies and emergency evacuation architectures.
An Automatic Rescue Device (ARD) is a critical emergency electronic unit designed to safeguard elevator operations. In the event of a sudden utility blackout or phase failure, passengers can become trapped in the lift car between floors. A highly responsive ARD immediately assumes control, shifting the power source to its integrated battery backup bank. Utilizing state-of-the-art solid-state microprocessors, the ARD performs critical calculations: it identifies the direction requiring the least mechanical torque (least-load direction path), drives the traction motor to the nearest landing level, and commands the door operator to open safely, allowing passengers to exit without delay.
From an industrial perspective, the integration of ARD systems is no longer a luxury auxiliary upgrade. It has evolved into a baseline standard mandated by national construction rules, municipal engineering directives, and insurance safety policies globally. Modern VVVF (Variable Voltage Variable Frequency) speed governors and direct drive PMSM (Permanent Magnet Synchronous Motors) require high-fidelity pure sine wave power inputs during emergency phases. Leading manufacturing hubs, such as Ascom Elevator's specialized plants in China, have optimized these devices to deliver seamless transitions, minimizing transient voltage surges and securing sensitive elevator controllers.
Rapid high-density urbanization and the proliferation of super-tall skyscrapers present substantial engineering challenges. Municipalities in Asia-Pacific, North America, and Europe have enacted strict legislation detailing emergency evacuation operations. For example, standards such as EN 81-20 / EN 81-50 in Europe and ASME A17.1 in North America explicitly outline the functional mandates for elevator safety components, driving elevator OEMs to include premium ARDs at the factory floor level.
Globally, the market for automatic rescue devices is driven by three main factors:
Exploring the electrical logic, battery management, and smart controllers of industrial-grade ARDs.
An industrial-grade Automatic Rescue Device functions through complex coordination between electrical logic, power conversion systems, and smart sensor networks. Below, we examine the typical functional steps of a modern ARD during a main power failure:
| Phase | Functional Description | Subsystem Active | Time Duration |
|---|---|---|---|
| 1. Detection | Sensors detect utility phase loss, under-voltage, or complete blackout. The primary relay triggers safety lockdowns. | Voltage Sensor, Main Control MCU | < 1.5 seconds |
| 2. Isolation | The elevator is safely isolated from the main grid to prevent hazard feedback when power returns. | Mechanical Interlocks, Isolation Contactors | < 3.0 seconds |
| 3. Evaluation | ARD measures current in both up and down directions to calculate the lower load path. | Load-Sensing Algorithm, VVVF Drive Interface | 2 - 4 seconds |
| 4. Traction | Power is drawn from batteries to drive the traction motor at rescue speed towards the target landing. | Battery Bank, DC-AC Inverter Module | 10 - 30 seconds |
| 5. Door Release | Upon reaching the floor sensor, the ARD sends an unlock and door-open command, releasing passengers. | Door Operator Interface, Leveling Switches | 5 - 10 seconds |
Modern ARDs seamlessly coordinate with Variable Voltage Variable Frequency drives, controlling starting currents to protect traction motors and system components.
Features intelligent dual-mode charging, thermal regulation, and automatic deep discharge protection, keeping the battery bank ready for any emergency.
Provides remote system status telemetry, real-time battery monitoring, and automated test reports via RS485 or CAN bus protocols.
Historical ARD systems suffered from short battery life, high failure rates, and rough operation. Modern engineering has resolved these issues through several key breakthroughs:
Customized emergency evacuation configurations designed for diverse building environments.
In medical clinics and emergency trauma centers, transport delays can be life-threatening. Patient elevators carrying stretchers, oxygen support systems, and medical teams require immediate and reliable rescue support. Hospital elevator systems are designed with high-capacity ARDs capable of handling heavy loads (up to 2500kg or more) and driving elevator cars quickly to the nearest floor. They are also integrated directly into the hospital's priority controls, ensuring rescue systems prioritize designated medical floors when emergency power is activated.
Hypermarkets, shopping complexes, and transit airports use vertical systems, including moving walkways and shopping cart escalators, alongside passenger elevators. If a power outage occurs on a busy escalator or moving walk, the sudden stop can cause falls and injuries. ARD solutions for commercial spaces feature controlled regenerative braking, bringing escalators to a smooth, gradual stop rather than a sudden halt. Simultaneously, adjacent elevators are brought to the nearest floor to prevent trapping large numbers of shoppers.
Modern apartment buildings often operate without round-the-clock maintenance staff. If a resident becomes trapped late at night, rescue times can be long. For these buildings, cost-efficiency and high reliability are critical. Modern home and residential elevators feature compact, cabinet-integrated ARD devices. These systems run automatic self-diagnostic routines weekly, ensuring the backup power supplies are fully operational without requiring frequent manual inspections.
Ascom Elevator is a professional Elevators Manufacturer and Supplier in China, providing premium Fuji Lifts & Elevators. Our comprehensive product range covers Passenger elevators, Home elevators, Sightseeing elevators, Cargo elevators, Escalators, Shopping cart escalators, and more.
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