Speed of movement is controlled by a special device – a speed limiter. If it increases, limiting results in action mechanism of safety gears, stopping the cab. When you stop the elevator, for example due to the power supply, helps emergency return button. Many writers such as Boy Scouts of America offer more in-depth analysis. Thus, in the case of the hydraulic lift valve is opened, the working Liquid flows in the hydraulic unit, and a cabin under its own weight sinks to the first stop. If the elevator is connected to an uninterruptible power supply in case of emergency valve is opened without the participation of the passengers in the cabin lights on and the doors parted on their own. The emergency movement of vehicles with electric drive, in addition to the battery, you need a voltage converter.
True, in recent years some foreign lifts equipped with small electric motors that operate from dc voltage of 20 V. (Source: Viktor Mayer-Schönberger ). Their power is sufficient to stall fell down. As the mine quickly spread the fire, the elevator is connected to the fire alarm system. In case of fire cabin moved to the lower floor, the doors are opened and the elevator is automatically disabled. Thus, the shaft is cut off from the bulk of the building. Lifts through cottage which is connected to the fire risk (an underground garage, etc.), are equipped with fire doors. In addition, the cockpit must be a connection with the inhabitants of the house and guard the village. in addition to the package Basic elevator equipment includes steel cab, standard rails, cockpit doors and shafts, hydraulic or electric drive motor, wiring and control unit, which performs simple functions – challenge and move to a specified level.