Garage system consists of two parts, the first part is the door itself, the system of springs and cables from two sides - it also works without electricity (manual mode). The second part consists of the engine, security sensors, remote, and wall button. (Electric) If the first part is not working, then the second part will not work and can crash the system when you start. Each side of the door there are two cables of steel . These cables are connected to the drum (wheel) located at the top of the door from both sides . This Drums are connected to a bar of the iron across the door from two sides . And the part where the energy to lift this door are the springs that hold on to the metal bar . Dimensions of the springs are determined by height and weight of the door. The number of the rotations of the springs depends on the height of the garage door.