Mounting and Wiring VMA1200 Series Controllers Technical Bulletin
3
Key Concepts
VMA Position and Orientation
Note:
Extra mounting brackets, linkage, or couplers are not
required for standard mounting.
Consider the following when positioning and orienting the VMA:
•
Mount the VMA on a vertical and flat surface where it functions
best, such as the side of the VAV box.
•
Route the tubing so a portion of it is lower than the pressure sensor
or loop the tubing. This creates a moisture trap that prevents any
condensation from entering the sensor.
•
Do not make any sharp bends in the tubing. This could collapse the
tube and block the pressure path.
•
Ensure that wiring terminals and service pin are accessible.
•
Make sure the
VMA1200 Installation Bulletin (Part No. 24-9310-5)
is available for properly identifying terminals.
•
Locate the VMA so that it has adequate clearance for future
servicing and is protected from moisture and corrosive fumes.
Determine and Set Damper Polarity
Damper polarity is established upon installation. Incorrect damper
positions in a zone easily result in misdiagnosis of readings, resulting
in unnecessary repetition of setup and diagnostics.
Many dampers seal properly only when closed in the rotation direction
specified by the manufacturer. To simplify maintenance, use the same
direction to close on all boxes of the same type.
To determine whether the damper is closed Clockwise (CW) or
Counterclockwise (CCW):
●
Visually verify which direction opens the damper before duct work
is completed and note the information for future reference.
●
Look up the manufacturer’s damper model specifications.
●
Once there is airflow in the zone, use a commissioning tool to
command the actuator to 100%. If this causes the flow to decrease,
it is an indication that the Damper Polarity configuration property
must be reversed from its current setting.