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WARNING
Rotating Components!
Failure to disconnect power before servicing could
result in rotating components cutting and slashing
technician which could result in death or serious
injury.
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized.
6. With the outside air dampers fully closed and the
supply fan operating at 100% airflow requirements,
measure the return static pressure at the location
determined in step 1.
7. Press the STOP key at the user interface in the unit
control panel to stop the fan operation.
8. Open the field supplied main power disconnect switch
upstream of the rooftop unit. Lock the disconnect
switch in the "Open" position while working on the
dampers.
9. Locate the static pressure reading in
and determine which damper needs to be adjusted and
the degree reading. Proceed to the appropriate damper
actuator procedure.
To Adjust the Outside Air Damper Actuators
1. Remove the shaft coupling from the damper shaft by
loosening the bolt and removing the retainer clip. Be
careful not to rotate the shaft.
2. Position the shaft coupling so that the indicator points
to the degree value obtained from
coupling is adjustable in 5 degree increments.
3. Replace the retainer clip and tighten the shaft coupling
on the shaft (120-180 in-lbs).
4. Close the disconnect switch or circuit protector switch
that provides the supply power to the unit terminal block
or the unit mounted disconnect switch.
5. Rotate the actuator control signal dial to Auto-Adapt.
RT-SVX073A-EN
"Table 46, p. 170,"
Step
9. The shaft
The actuator will drive open and then closed to
determine the new open and closed positions.
6. Return the actuator control signal dial to 2-10 VDC
Modulating input signal position.
7. Plug the holes drilled in the cabinet after the proper
airfow has been established.
To Adjust the Return Damper Actuators
1. Support or secure the damper blades in the wide open
position.
Note: Gravity will cause the damper to close. Support
or secure the damper blades while removing the
actuator to prevent unexpected damper rotation.
2. Do not remove the shaft coupling from the shaft.
Remove the retainer clip from the shaft coupling.
3. Unscrew the actuator bracket from the damper wall.
4. Slide the actuator down the damper shaft off of the
shaft coupling.
5. Rotate the actuator and reinstall the shaft coupling in
the actuator so that the indicator points to the degree
value obtained in Step 11. The shaft coupling is
adjustable in 5 degree increments.
6. Replace the retainer clip and remove the blade stops to
allow the blades to rotate.
7. Rotate the actuator to the original position and reattach
the actuator bracket to the damper wall.
8. Close the disconnect switch or circuit protector switch
that provides the supply power to the unit terminal block
or the unit mounted disconnect switch.
9. Rotate the actuator control signal dial to Auto-Adapt.
The actuator will drive open and then closed to
determine the new open and closed positions.
10. Return the actuator control signal dial to the factory set
input signal position.
11. Plug the holes drilled in the cabinet after the proper
airfow has been established.
Unit Startup
141
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