D+AS MAGAZINE

TECHNICAL TIPS — How to Adjust the Sensing Edge Shut-Off Switch

© 2003 Door & Access Systems
Publish Date: Spring 2003
Author: Ed Elliott and Clay Warix
Page 63


TECHNICAL TIPS

How to Adjust the Sensing Edge Shut-Off Switch
By Ed Elliott of The Cookson Company
and Clay Warix of Overhead Door Corporation

The sensing edge shut-off switch is designed to prevent a door from automatically opening or reversing a door when the door is in the closed position.

This switch is an auxiliary switch within a motor operator that is activated with the traveling nut (part of the rotary limit switch mechanism). The switch is located on the close side of the limit switch assembly so that it is activated just before the door reaches the closed limit. When the switch is activated, the sensing edge is disabled, and the door will no longer stop or reverse if an obstruction is encountered.

For greater safety, you should verify and adjust the sensing edge activation height. The sensing edge must remain active at least six inches from the floor.

To adjust, change the position of the sensing edge shut-off switch. This switch’s location is factory-set for each motor operator, but different doors may affect the edge’s operating range. Barrel diameter, barrel rings, and/or sprocket ratio may affect the range.

Adjusting this switch is relatively simple. The switch is mounted in slotted holes, and the mounting screw heads are typically accessible from the exterior of the operator.

When adjusting this switch, verify the activation height of the sensing edge, and verify that the door will not automatically open if the edge is activated when the door is closed. Further, the door should be cycled several times to check for consistency of the setting.

Always refer to the motor operator manufacturer’s instructions for specific adjustment directions.