DeZURIK
D10389
Page 16
November 2020
Lockable Model
(continued)
Unlocked Condition
Under normal unlocked operating conditions, both of the lock screws are backed out of the housing to
allow the gear to rotate freely in either direction. To be fully disengaged, the distance from the housing
to the end of each lock screw must be at least 2¼" (57 mm). To hold the lock screws in position, tighten
the jam nuts to 38 ± 5 foot pounds (52 ± 7 Nm).
Figure 8
—Unlocked Condition
Locked Closed Condition
Follow the steps below to change the unit from the unlocked condition to the locked closed position.
Refer to Figure 9 for component identification. Before proceeding, ensure the open and closed position
stops are properly adjusted as described in the “Position Stops” section.
1. Operate the actuator to the fully closed (clockwise) position.
Adjusting the wrong screw does not lock the actuator, and can result in personal injury
or equipment damage. Adjust only the LEFT-SIDE lock screw to lock the actuator in the
closed position.
2. Loosen the jam nut (B65) on the
left
side lock screw (B64), as viewed when facing the top of
the heads of the lock screws.
3. Hold the lock screw from turning, and turn the jam nut several turns counterclockwise, to the
head of the lock screw.
4. Turn the
left
side lock screw clockwise several turns until resistance is felt from the lock screw
contacting the notch in the gear (B8).
5. Tighten the lock screw to 5 to 10 foot pounds (7 to 14 Nm) to assure that the lock screw is
contacting the gear.
6. Turn the
left
side jam nut clockwise against the actuator housing, then hold the lock screw and
tighten the jam nut to 38 ± 5 foot pounds (52 ± 7 Nm).
