Cable fail-safe redundancy: Based on the proper setting of the drums on the torsion shaft, the two lift cables divide the lifting force equally to keep the door level as it rises. This not only levels the door, but also provides a fail-safe mechanism. If one of the cables should fail, such as from breaking or losing its end attachment, the other cable will then carry the full weight of the door. This will pull the door up on one side with twice the normal force, while the other side falls from its now unsupported weight, tending to make the door bind in its tracks and jam. Although not foolproof, this is a safety feature of the design which keeps the door from falling catastrophically if a cable were to fail while the door was traveling. The jammed condition also prevents a lowered door from opening with the hazard of a single broken cable, further minimizing the chances of both cables failing. Since if one cable fails the other must sustain the full weight of the door, the cables and attachments are rated many times the normal working load of half the door weight. A proper safety inspection of the door should include a critical look at the cables and their attachments.
And for some extra features, you'll appreciate accessing the system through the MyQ smartphone app. You can set up this Chamberlain opener to automatically close the door after 1, 5, or 10 minutes, which is great for people who are a bit forgetful. We also really like the motion-detecting control panel, which turns on lights whenever it records nearby movement.
Garage Door Repair