Compact unit of a robust welded structure, with built-in irreversible worm wheel reduction gear with spur wheel step, 3-phase AC-motor with coiled-in thermal protection. Drive shaft with double-sided drive arm, limit switch system and adjustable patented torque limiter between motor and reduction gear. This means that as soon as the motor stops – independent of door position – the irreversible worm gear locks the drive arm and thus the door leaves. A quick release by handle or – at option – by a pull cable control enables a manual operation of the door.

The limit switch
On the reduction is a box mounted with limit switch ES10, this can be connected with a separate controller which can be chosen out of the LST/WST range. The limit circuit then consists of a potential-free limit switch, a control current limit switch for determining the end positions and a safety switch for each direction of rotation.