Mounting Instructions; Mounting Position - Distech Controls ECB-VAVS Installation Manual

Mounting Instructions

Each controller is specially designed for easy installation either directly
on an air duct or in a panel by using the integrated mounting collar and
the screw that is provided with the controller. This mounting arrange-
ment opposes the torque applied to the damper shaft.

Mounting Position

To prevent condensation on the VAV box's damper shaft from entering
the controller's electronics, the controller's mounting orientation should
be any position above the damper shaft (between 0 and 180°) so that
any condensation from the damper shaft will fall away from the con-
troller's electronics. Further countermeasures may be required in some
installations. This is important in hot, humid climates where the VAV
box is located near exterior doors or loading bays that may be blocked
open or when the VAV box air supply is below 50°F (10°C).
0°
Figure 6: Permitted Mounting Position Angle Range
Mounting Procedure for Terminal Covers
Terminal covers can be added to any VAV controller to protect inadver-
tent contact with the controller's electrical connections.
£
A terminal cover kit can be added to both sides of the controller.
Controllers with terminal block covers can only be mounted on a flat
surface that is sufficiently large to provide space around the installation.
In this scenario, conductors must be made inaccessible and wiring
must comply with local wiring regulations and methods appropriate for
fixed equipment installation in a building (the use of cable conduits and
trunking for example).
1. Separate the cover from the base of the terminal covers.
2. Attach the base of the terminal cover(s) to the underside of the VAV
controller's body with the tabs shown in Figure 7 .
3. Install the VAV controller according to the next procedure, VAV Con-
troller Mounting Procedure.
Figure 7: Terminal Cover Attachment Tabs
4. Connect and wire the controller according to the procedures shown
later in this document.
90°
VAV Box Shaft
270°
VAV Controller Mounting Procedure
Mount the controller as follows:
1. Configure the controller's DIP switches. See Figure 5.
2. The VAV controller comes with the sliding grommet pre-installed.
3. Orient the controller into position on to the damper shaft so that
wiring connections are easily accessible. The controller must be fit-
ted onto the shaft such that the base of the controller is parallel to
the VAV box (perpendicular to the damper shaft). If the damper
shaft has an external bushing that prevents the controller from be-
ing mounted flush to the side of the VAV box, use a spacer of the
same thickness to compensate and to ensure the controller is at a
right-angle to the shaft to prevent binding.
4. Screw the controller onto the VAV box through the controller's Slid-
ing Grommet. The sliding grommet allows the controller to move
back and forth when the VAV box's damper shaft is off center. En-
sure 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 8), attach the controller to
the VAV box with the 1" [25mm] screw provided with the controller
(Figure 9) through the controller's sliding grommet as shown in Fig-
ure 11. 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 controller.
180°
Figure 8: Screwdriver Shaft Extension
Figure 9: 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.
5. Find the damper position by the marking typically found on the end
of the damper shaft.
Figure 10:
6. 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
7. 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 mechanical end-stop to either the fully closed position
(90° boxes) or the fully open position (45° and 60° boxes).
8. 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
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.
9. Tighten the U-Bolt clamp on to the damper shaft using an 5/16 in (8
mm) wrench or socket. Tighten the bolts between 100 and 130 lb-in
(11 and 15 N-m).
10. Test for free damper shaft movement: Press and hold down the
Actuator Clutch For Manual Adjustment button and manually turn
the actuator coupling to be certain that the actuator can rotate from
full closed to full open positions without binding.
At Installation,
Align
Grommet to
this Mark
Sliding Grommet
Typical Damper Shaft End Marking
preset for
Operational
Grommet
Travel
Range
90° boxes.
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