Distech Controls ECL-VAVS Installation Manual page 5

3. Screw the controller onto the VAV box through the controller's Sliding Grommet. The sliding grommet allows the controller to move back and forth
when the VAV box's damper shaft is off center. Ensure to center the grommet along its travel range and ensure that the screw enters the VAV box at
a right angle. Using a power screwdriver with a 6" extension (Figure 7), attach the controller to the VAV box with the 1" [25mm] screw provided with
the controller (Figure 8) through the controller's sliding grommet as shown in Figure 10. Otherwise, mark the positions for the screw on the VAV box
with a punch and then drill a hole the into the VAV box. Then attach the controller to the VAV box with the 1" [25mm] screw provided with the con-
troller.
Figure 7: Screwdriver Shaft Extension
Figure 8: Supplied Mounting Hardware – Drive the screw at a right-angle to the VAV Box
Avoid over-tightening the screw so as to not strip the threads. Make sure the screw does not pierce too far into the VAV box and interfere
with damper blade movement.
4. Find the damper position by the marking typically found on the end of the damper shaft.
Figure 9: Typical Damper Shaft End Marking
5. Determine the direction required to close the damper: Clockwise (CW) or Counterclockwise (CCW). Turn the damper shaft with a pair of pliers to fully
close the damper for 90° boxes or fully open the damper for 45° or 60° boxes
6. Press and hold down the Actuator Clutch for Manual Adjustment button (see Figure 3), and turn the controller's shaft coupler until it touches the me-
chanical end-stop to either the fully closed position (90° boxes) or the fully open position (45° and 60° boxes).
7. For 90° VAV boxes: If the damper closes CCW, turn the coupler to the CCW mechanical stop limit. If the damper closes CW, turn the coupler to the
CW mechanical stop limit. The open mechanical stop is factory preset for 90° boxes.
For 45° and 60° VAV boxes: The mechanical stops must be set for both the fully closed and fully open damper positions. By installing the controller at
the fully open position, the controller provides the open mechanical stop for 45° and 60° boxes. The closed damper seal provides the fully closed
stop.
8. Tighten the U-Bolt clamp on to the damper shaft using an 5/16 in. wrench or socket. Tighten the bolts between 100 and 130 lb-in.
9. Test for free damper shaft movement: Press and hold down the Actuator Clutch For Manual Adjustment button and manually turn the actuator cou-
pling to be certain that the actuator can rotate from full closed to full open positions without binding.
10. Connect the VAV box's flow sensor tubing to the controller's Pressure Sensor Inputs . The connection is polarity free (high-low ports are interchange-
able). Create a condensation trap in the pneumatic tubing by forming it into a vertical loop.
11. Finalize the installation by rotating the damper to the full open position.
At Installation,
Align
Grommet to
this Mark
Sliding Grommet
Operational
Grommet
Travel
Range
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