27
31-00083—02
Fig. 31. Single Duct, Pressure Independent Cooling, with
Analog Parallel Fan.
PARALLEL ANALOG - FAN
Use this only with single duct configurations. The Analog fan is
a variable speed fan that controls the amount of return air or
return plenum air to the space. The Analog fan acts in
opposite to the cooling duct damper position for pressure
dependent operation, or in opposite to the cooling duct flow for
pressure independent.
See Fig. 32 for Modes for Single Duct, Pressure Independent
Cooling, with Parallel Fan.
Fig. 32. Modes for Single Duct, Pressure Independent
Cooling, with Parallel Fan.
EXHAUST TRACKING FLOW CONTROL
An example of Exhaust Tracking is shown in Fig. 33. To
configure Exhaust Tracking Flow Control Application in the
tool, follow the configurations shown in the table below (see
“Flow balancing” on page 34 for more information on
parameters).
Additionally, Bind the nvoFlowtTrack of controller number 1 to
the nviFlowtTrack of number 2, the nvoFlowtTrack of number 2
to the nviFlowtTrack of number 3, the nvoFlowtTrack of
number 3 to the nviFlowtTrack of number 4.
Flow Tracking Application Notes:
1.
Flow tracking is intended for noncritical, slow respond-
ing commercial building zone pressurization control
sequences. This means that average pressurization can
be maintained if disturbances are slow acting, but fast
disturbances may result in temporary short term imbal-
ances. Do not apply the VAV Flow Tracking option in life
safety or industrial environments such as clean rooms,
fume hoods, or bio hazard control.
2.
Flow tracking requires high resolution air flow damper
actuators. Floating actuators are recommend.
M33871
FLOW
SENSOR
SUPPLY AIR
55 DEGREES F
FLOAT
DAMPER
PARALLEL
FAN
DISCHARGE
AIR
T7770
SPACE
AIR
TEMP
RETURN AIR
FROM PLENUM
60
70
80
1 1 1 1 1 1 1 2 2 2 2 2
3 4 5 6 7 8 9 0 1 2 3 4
UI-4
COM
UI-3
UI-2
COM
UI-1*
AO
-2
COM
AO
-1
COM
DO-2
DO-1
1 1
1 2 3 4 5 6 7 8 9 0 1 2
COM
DO-4
COM
DO-3
NET
-2
NE1-2
S-B
U
S 2
S-B
U
S 1
20VDC
EGND
24V
A
C COM
24V
A
C
M12800
COLD
HOT
COLD DUCT
PWM FAN 100 PERCENT
MIN
FLOW
MAX
FLOW
MIN
FLOW
MAX
FLOW
HeatOccSpt
CoolOccSpt
CVL
Controller
Box Type
Selected in the
tool
Flow Type Selected in
the tool
1
Single Duct
SD_Normal_Flow
2
Single Duct
SD_Normal_Flow
3
Single Duct
SD_Normal_Flow
4
Flow Tracking
FLOW_Tracking