The EP engine gearboxes are maintenance-free, compact power units for generating ventilation, screening and lifting systems in greenhouses and livestock sheds. Engine gearboxes are supplied with fixing bolts and springtime washers. Motors can be sprocket drive or built with winch or belt drum. Includes a self-braking worm gear tranny with a Ventilation Screening And Lifting Gearbox Greenhouse Geared Motors System patented included linear limit switch program with duty and protection switches having exceptional switching precision.