LiftMaster BG790 BG790 Manual - Page 11

INSTALLATION LIMIT SWITCH ADJUSTMENTS CLOSE LIMIT SWITCH The CLOSE limit switch is preset at the factory. If you rotated the pulley in section Arm and Turnbuckle Shaft Adjustments, you will need to reset the cam on the CLOSE limit switch. 1. Loosen the set screw on the cam. Then rotate the cam in the close direction so that the switch is activated when the gate arm is in its lowest position (Figure 12). 2. When the cam is in the desired position, retighten the set screw. This adjustment may have to be fine tuned after turning on power and running the unit for the first time. Figure 12 Open Limit Switch Close Limit Switch Auxiliary Close Limit Switch AUXILIARY CLOSE LIMIT SWITCH The AUXILIARY CLOSE limit switch is preset at the factory. If you made an adjustment to the CLOSE cam, you will need to adjust the cam on the AUXILIARY CLOSE limit switch also. 1. Position the AUXILIARY CLOSE cam slightly ahead of the CLOSE cam. When the gate arm is on its down travel, the AUXILIARY CLOSE switch will activate just before the CLOSE switch. 2. When the cam is in the desired position, retighten the set screw. OPEN LIMIT SWITCH The OPEN limit switch is preset at the factory. This setting may have to be fine tuned after running the unit for the first time. 1. Loosen the OPEN cam and rotate in the open direction until the switch is activated (Figure 12). 2. Retighten the cam. OPEN Direction CLOSE Direction 11