The garage door is generally the largest moving object in a home. An improperly adjusted garage door opener can exert strong and deadly forces and might not reverse the garage door in an emergency. The garage door counterbalance springs should be properly adjusted in order for the safety reverse system to function properly. Thus, proper installation and maintenance are extremely important in order for the garage door and garage door opener to operate smoothly and safely.
Under U.S. federal law (UL 325), garage door openers manufactured for the U.S. since 1993 must include a secondary safety reversing system, such as photoelectric eyes or sensors, mounted near the floor. Other examples of safety reversing systems, allowed within the guideline of UL 325, include electric safety edges, which reverse with approximately 15 pounds of downward pressure, and a garage door and opener system without photo eyes, tested together, which reverses upon approximately 15 pounds of pressure.