How to resolve issues with an out of phase chain/belt drive opener

Some garage door openers have travel limits that are adjusted manually to tell the motor what direction to run and for how long. From the carton, the travel limit is set to the closed position. It is advised to not operate the unit until the installation is complete. If the unit operates without the chain or belt attached, the position of the motor will no longer match the trolley's position.

How do I know if my unit is out of phase?

• The door will not travel Up or Down regardless of how many times you increase the limit screws.
• The trolley is stuck in the Up or Down limit stop bolt. You will need to get the trolley off the stop bolt before proceeding to resolve the out of phase issue.

There are two ways to resolve an out of phase issue. The first way requires you to loosen the chain or belt enough to remove it off the sprocket. The second way requires you to remove the metal cover of the unit to make a manual adjustment to the limit switch assembly.

To resolve an out of phase issue by loosening the chain or belt

1. Unplug the power of the garage door opener.
2. Loosen the chain or belt tension and slip the chain or belt off the sprocket.
3. Plug the opener back in. Stand on a ladder so you can look down towards the top of the sprocket.
4. Activate the opener via remote control and watch the sprocket. When the sprocket rotates clockwise and stops by itself, the motor will be in a closed position.
5. Unplug the opener and reconnect the chain or belt, making sure the trolley is in the closed position. Tighten the tension on the chain or belt.
6. Plug the opener in and run the opener via remote control or wall-mounted door control.
7. If the opener does not run to the full open position, adjust the travel limits.

To resolve an out of phase issue by removing the metal cover

1. Run the opener to the open or close position, whichever it allows you to do.
2. Unplug the power of the garage door opener.
3. Remove the metal cover from the unit. It is held on with two screws on the top of each side of the metal cover and one or two screws on the bottom of each of the black panels.
4. Once you have removed the screws, hold on to both sides of the metal cover and pull out then down the cover.
5. Look at the limit switch assembly. This is a black plastic piece that houses three long white nylon travel screws. The two outer screws are the travel adjustment screws and the middle screw is driven by the drive shaft. On these screws are three contacts:
   • The contact with a brown wire attached represents the Down limit switch.
   • The contact with a yellow wire attached represents the Up limit switch.
   • The contact with a gray wire represents the positioning of the trolley. This contact will have two metal wings sticking out 
6. Increase the travel of both the Up and Down limits until they are maxed out on either side and are unable to increase any further.
   • Increase the Up contact with the yellow wire by turning the screw clockwise.
   • Increase the Down contact with the brown wire by turning the screw counter clockwise.
7. Decrease the Down contact with the brown wire 10 full turns clockwise.
8. Decrease the Up contact with the yellow wire 11 full turns counter clockwise.
9. Remove the helical gear, which is the little white gear at the end of the sprocket shaft. It is held on by an E-clip. The easiest way to remove the E-clip is to pull out the two pointed sides and slide the clip out.
10. Turn the gear on the middle screw so that the middle contact with the gray wire touches one of the travel limits.
    • If the trolley is in the closed position, turn the middle screw until the middle contact touches the Down travel contact with the brown wire.
    • If the trolley is in the open position, turn the middle screw until the middle contact touches the Up travel contact with the yellow wire.
11. Re-install the helical gear back on, and snap the E-clip back in.
12. Plug the power back on the opener and test.
13. Make adjustments to the travel limits if necessary.

See Also:Chain/belt drive garage door opener runs in the wrong direction