AMD-xx-TD Series Damper Without a
Factory Supplied Controller
Units ordered without a factory supplied controller are
supplied with a standard modulating actuator . The Vari-
Green transmitter and actuator are wired to a factory
supplied terminal block .
Figure 1
shows the field wiring
side of the terminal block .
The 0-10 VDC analog output at terminals 3 and 4 comes
from the Vari-Green transmitter and is proportional
to the velocity going through the AMD-xx-TD . A 10
VDC signal represents the maximum velocity that was
selected at the time the unit was ordered . The selected
maximum velocity and the area of the AMD-xx-TD
are listed on a label adjacent to the terminal block . An
example of how you can determine the velocity and/or
cfm going through the unit is shown below .
1 2 3 4 5 6
9
7 8
S
S
~
24VAC
0-10VDC Output
Proportional to
Flow
Control
Signal to
Actuator
AMD-XX-TD w/o Factory
Supplied Controller
Factory Installed
Terminal Block
On multiple section high dampers, the
actuators on the sections without the
terminal block will need to be field wired
into Terminals 1, 2, & 5
***
***
Measured Velocity
= Max Velocity * (Measured
Voltage / 10)
Measured Velocity
= 2,000 * (3 .5 / 10)
Measured Velocity
= 700 fpm
and
Measured CFM
= Measured Velocity * Area
Measured CFM
= 700 fpm * 4 ft2
Measured CFM
= 2,800 cfm
AMD-xx-TD Series Ordered with a
Factory Supplied Controller
When you order a factory supplied controller, it comes
with a Greenheck exclusive VAF24-BAC-GTD actuator
which has the controller integrate inside of it . The
actuator/controller is configured by the factory at the
time the unit was ordered for either analog or BACnet
operation . This selection is made by setting the Setpoint
Source datapoint to Local AI or BACnet . A complete list
of all the BACnet datapoints is listed in Table 1 (page 7) .
AMD-xx-TD Series Damper with an
Analog Factory Supplied Controller
Figure 2
shows field wiring for an AMD-xx-TD ordered
with a factory supplied controller configured for analog
operation .
1 2 3 4 5 6
9
7 8
S
S
~
24VAC
Factory Installed
Terminal Block
0-10 VDC Output
Proportional to
Flow
0-10VDC
Input
Setpoint
AMD-XX-TD w/Analog
Factory Supplied
Controller
Figure 2
Figure 1
Example 1:
Determine the CFM from a 24 in . x 24 in . AMD-xx-TD
(area of 4 ft
2
) with a selected maximum velocity of 2,000
fpm and a voltage reading across terminals 3 and 4 of
3 .5 VDC .
4
Air Measuring Dampers: AMD-XX-TD Series
