Commercial Door Operator Safety Systems - DDM Garage Doors Blog

Posted August 21st, 2020 at 5:53 pm by Dan Musick

Commercial door operator manufacturers have designed three standard safety systems.

First is the mechanical clutch that slips when the door is obstructed.

An image of the interior of a LiftMaster commercial door operator.
A spring-loaded pulley, pressure plate, and disc stop the travel of the operator if the door is obstructed.

The second design is the eye sensor system. If a vehicle or a person passes under the door and blocks the eyes, the door operator will reverse the door until it raises to the open position.

A view of safety eyes installed on a Commercial Door Operator as part of the safety system.
Safety eyes prevent the door from injuring people and damaging vehicles that might be under the door as it closes.

The third safety system for commercial door operators is the internal electromechanical sensor or an electrical sensor. These can detect changes in motor speed. If there is an obstruction such as a locked door, a broken spring or a broken cable, the motor speed will slow and stop the door if it is opening. Otherwise, the motor will stop the door and cause it to open if the obstruction occurs as the door closes.

A closure view of RPM sensor in a LiftMaster commercial door operator.
A plastic wheel with “windows” rotates through the infrared RPM sensor and counts the motor revolutions to stop and reverse the operator travel.

More information is on our YouTube video by the same name.



This entry was filed under Products, Technical Support. You can follow any responses to this entry through the RSS 2.0 feed.

Comments are closed.


Unmatched Support. The Right Part. DIY with Confidence!

YES, WE'RE OPEN FOR BUSINESS! DDM is considered a life-sustaining company because we are an internet retail company that provides essential products. Due to the recent outbreak of Coronavirus, however, we are changing our local order pickup policy at our West Chicago location. To pick up an order you will need to order first. The quickest way is to order in advance through our online shopping cart. There you can select the local pickup option. Or, you can call 630-293-1337 for assistance, to confirm availability of parts, and to place your order. Once ordered, your parts will be available for pickup in the lobby of our north side front entrance. Longer items will be picked up on the south side loading dock. Please honor the six foot social distancing rule. Thank you for your patience and understanding as we all navigate this challenge together. More information is available on our blog titled DDM Adjusts to the COVID-19 Coronavirus. In the same article you will also find documentation and an answer to the question: "Is a garage door repair company a life sustaining business?"

PLEASE NOTE: DUE TO COVID-19 SHIPPING TIMES ARE NOT GUARANTEED, EVEN ON NEXT DAY AND SECOND DAY SHIPMENTS. NORMAL TRANSIT TIMES DO NOT APPLY.