VAV-SVX02B-EN
14
Constant Volume Dual-Duct
Calibration (3011)
This calibration procedure is used when
a constant volume of air must be
maintained through a unit. On a dual-
duct unit, a constant-volume discharge
sensor is used to measure the air
leaving the unit. The PVR controlling to a
constant-volume of air leaving the unit
uses the discharge sensor to maintain
the specified cfm.
This PVR does not require a thermostat
connected to the PVR.
The following procedure must be used
when calibrating a constant-volume
dual-duct unit. See Figure 15 for a
typical piping diagram.
1. Set t-stat to full heat.
2. Set LO thermostat (maximum) to the
desired maximum flow on the
heating deck.
3. Set t-stat to full cool.
4. Set HI thermostat (minimum) to
the desired minimum flow on the
heating deck.
5. Set LO thermostat adjustment knob
on cooling deck (CV deck) to desired
constant-volume.
6. Exercise the system to check flows
for proper operation.
Figure 15–Typical Constant-Volume
Dual-Duct Piping Diagram
Constant-Volume Dual-Duct
Calibration (3011)
Restrictor
Tee
(137.9)
20
S
20
(137.9)
S
20
(137.9)
S
Two-Pipe
Remote-Mounted
T-Stat
(Direct-Acting)
Actuator
HI
LO
Outlet
HI
LO
Constant-Volume
Flow Ring
Heating
Valve
g
Cooling
Valve
Normally-
Open
Normally-
Open
Volume
Regulator
Volume
Regulator
L
H
M
B
G
T
M
B
G
H
L
T
Actuator
