Mounting - Metasys - MS-VMA1615 - MS-VMA1626 - MS-VMA 1628 - MS-VMA1630 - Field Device - VMA16 VAV Modular Assembly

Observe the following guidelines when mounting a VMA :

• Ensure that the mounting surface can support the controller and any user-supplied enclosure. electronics. Mount the controller vertically above the damper shaft to allow any shaft condensation to fall away from the controller. Additional measures may be required in some installations.

• Mount the controller on a hard, even surface whenever possible.

• Use shims or washers to mount the controller securely and evenly on the mounting surface.

• Mount the controller in an area free of corrosive vapors that matches the ambient conditions specified in the Technical specifications section.

• Provide sufficient space around the controller for cable and wire connections and adequate ventilation through the controller (at least 50 mm [2 in.] on the top, bottom, sides, and front of the controllers).

• electronics. Mount the controller vertically above the damper shaft to allow anyDo not mount the controller in areas where electromagnetic emissions from other devices or wiring can interfere with controller communication.

• Avoid mounting the controller on surfaces with excessive vibration.
• When using the VMA1615/1626/1628/1630 to replace a VMA1610 or VMA1620 controller, plug the unused open hole in the duct work from the original VMA mounting if possible. Plug the hole using the sheet metal screw from the original installation (preferred option).

On panel or enclosure mount applications, observe these additional guidelines:

• Do not install the controller in an airtight enclosure.

• Mount the controller so that the enclosure walls do not obstruct cover removal or ventilation through the controller.

• Mount the controller so that the power transformer and other devices do not radiate excessive heat to the controller.

To mount the controllers, complete the following steps:

1. Set all the switches on the field controller to their known settings.
2. Place the controller in the proper mounting position on the damper shaft so that the wiring connections are easily accessible. Make sure the controller base is parallel to the VAV box (perpendicular to the damper shaft). If needed, use a spacer to offset tipping of the controller caused by the shaft bushings.
   Note: Use the alignment marks to center the captive spacer to ensure sufficient movement in either direction.
3. Secure the self-drilling No. 10 screw through the captive spacer (Figure 1) with a power screwdriver and 100 mm (4 in.) extension socket. Otherwise, use a punch to mark the position of the shoulder washer, and then drill a hole into the VAV box using a 3.5 mm (9/64 in.) drill bit. Insert the mounting screw and tighten against the spacer. For the VMA1628 models, use the additional 1.25 inch screw to mount to one of the two holes provided near the actuator opening (see Figure 1) to mount the controller.
   Important: Do not overtighten the screw, or the threads may strip. If mounting to the VAV box, make sure the screws do not interfere with damper blade movement.
4. Locate the damper position using the typical marking on the end of the damper shaft as shown in the following figure.
   Figure 1. Typical Damper End Shaft Icons
   

   

   
   
5. Note the direction, clockwise (CW) or counterclockwise (CCW), required to close the damper. Grasp the damper shaft firmly with pliers, and either manually close the damper for 90° boxes or manually open the damper for 45° or 60° boxes.
6. Push down and hold the Manual Override button (see Physical features) and turn the controller coupler until it contacts the mechanical end-stop at either the full-closed (90° boxes) or full-open (45° and 60° boxes) position.
7. If the damper for a 90° box closes CCW, rotate the coupler to the CCW mechanical limit. If the damper for a 90° box closes CW, rotate the coupler to the CW mechanical limit. The open end-stop is automatically set for 90° boxes. For 45° and 60° boxes, hard stops must be provided at both full-closed and full-open damper positions. By installing the controller at the full-open position, the controller provides the open stop for 45° and 60° boxes. The closed damper seal provides the full-closed stop.
   Note: The integrated actuator has a stroke time of 60 seconds for 90° of travel. The stroke time is the amount of time (in seconds) that it takes the actuator to move from the fully closed to fully opened position or from fully open to fully closed position. For proper operation, the actuator stroke time must be configured in the CCT application based on the actual time it takes the actuator to drive the damper. The default setting is 60 seconds (for 90° VAV boxes). For 45° and 60° VAV boxes, the actuator stroke time must be adjusted. Refer to Controller Tool Help (LIT-12011147) for instructions on setting the actuator stroke time in the application.
8. All models are compact in size and can be easily installed on VAV boxes. The models have either a round shaft up to 13 mm in diameter or a 10 mm square shaft. Tighten the square coupler bolt to the shaft using an 8 mm (5/16 in.) wrench or 10 mm (3/8 in.) 12-point socket. Tighten to 10.5 to 11.5 N·m (95 to 105 lb·in).
9. (Skip this step if you are installing the VMA1626 model) Loop the pneumatic tubing (supplied by field personnel) to include a trap for condensation. Attach the needed length of tubing (supplied and installed by field personnel) to the dual port fitting on the controller and the other ends of the tubing to the pressure transducer in the VAV box application.
   Note: The controller uses a digital non-flow pressure sensor (all models except the VMA1626 ) with bidirectional flow operation. You can connect the high- and low-pressure DP tubes to either barbed fitting on the controller. You do not need to make a specific high- or low-side connection when you attach the tubing to the barbed fittings on the controller.
10. Push the Manual Override button, and turn the actuator coupling manually to ensure that the actuator can rotate from full-closed to full-open positions without binding.
11. Complete the mounting by rotating the damper to the full-open position.