SINGLE DUCT
Airflow
CAV (Constant Air Volume) Cooling
The airflow remains constant regardless of
changes in duct pressure or room temperature.
A room thermostat is not used.
80
60
40
20
Min..
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
RA 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Models: PESV, PECV, PQCV
Thermostat Branch Pressure, (psi)
Airflow
100
80
60
20
Min.
low
40
Max.
CAV
rF
CAV Cooling, Hot Water Reheat
The cold airflow remains constant regardless of
changes in duct pressure or room temperature.
As room temperature increases, the room
thermostat modulates the hot water coil valve
toward the closed position.
ate
tW
Control Option Code: OO
VAV Cooling, Hot Water Reheat
As the room temperature increases, the room
thermostat modulates the hot water coil
valve toward the closed position. On a further
increase in room temperature, the room
thermostat modulates the cold airflow from
the minimum to maximum setting.
Max.
CAV
100
V
Control Option Code: OO
VAV (Variable Air Volume) Cooling
As the room temperature increases, the room
thermostat modulates the cold airflow from
the minimum to the maximum setting.
Ho
O
terminal unit accessories
VA
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CONTROL SEQUENCES
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Model: PESV
Control Option Code: OO
VAV Cooling, Electric Reheat
As the room temperature increases, the room
thermostat de-energizes the electric heating
one step at a time. On a further increase
in room temperature, the room thermostat
modulates the cold airflow from the minimum
to the maximum setting.
CAV Cooling, Electric Reheat
The cold airflow remains constant regardless of
changes in duct pressure or room temperature.
As room temperature increases, the room
thermostat de-energizes the electric heating
coil one step at a time.
Airflow
100
80
20
Max.
Step 2
60
40
CAV
Step 3
Step 1
Min.
DA 0 1 2 3 4 5 6 7 8 910 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
CONTROL SEQUENCES
Model: PESV
Control Option Code: WU
VAV Cooling with Morning Warm-Up (MWU)
A separate 15 to 25 psi pneumatic signal line
to each terminal unit resets the controller
setpoint through a signal selector relay for
pressure independent hot airflow at the
maximum setting. Additional heat may be
provided by a heating coil on the discharge
of the unit.
Airflow
100
Max.
MWU
80
60
40
20
Min.
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Models: PESV, PECV, PQCV
O18
O18
When the warm-up signal is turned off, the
unit resumes normal cooling operation. As
the room temperature increases, the room
thermostat modulates the cold airflow from
the minimum to the maximum setting.
Thermostat Branch Pressure, (psi)
Control Sequences (continued)
terminal unit accessories
Total Airflow
Control Option Code: DM
VAV Cooling, Dual Minimum Flows, with
Reheat (Signal Line)
When the signal line is zero psi, a decrease in
room temperature modulates the cold airflow
from the maximum to the minimum setting.
Model: PESV
Control Option Code: DP
VAV Cooling, Dual Minimum Flows, with
Reheat (Dual Pressure Main)
At the summer main pressure (usually 18 psi)
a decrease in room temperature modulates the
airflow from maximum down to the minimum
setting.
Max.
100
When the signal line equals the alternate psi,
a decrease in room temperature modulates
the airflow from maximum to alternate
minimum setting. A further decrease in room
temperature modulates the hot water valve or
steps the electric coil for reheat.
80
60
40
20
Alt. Min.
Min.
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Thermostat Branch Pressure, (psi)
Airflow
At the winter main pressure (usually 23 psi),
a decrease in room temperature modulates
the airflow from maximum down to alternate
minimum setting. A further decrease in room
temperature modulates the hot water valve to
open or steps the electric coil on for reheat.
Max.
100
80
60
40
20
Alt. Min.
Min.
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Thermostat Branch Pressure, (psi)
Model: PESV
O
Airflow
Control Option Code: FF
100
Max.
Max.
80
Ho
60
tW
40
r
ate
VAV Cooling and VAV Heating, Equal Maximum
Flows (Flip-Flop)
A decrease in room temperature modulates the A further decrease in room temperature
airflow from maximum to minimum setting (at modulates the airflow from minimum to
room thermostat setpoint).
maximum setting and modulates the hot water
control valve to the open position.
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SINGLE DUCT
20
Min.
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Thermostat Branch Pressure, (psi)
Model: PESV
Max.
100
80
Min.
er
60
40
20
Min.
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Model: PESV
Thermostat Branch Pressure, (psi)
CONTROL SEQUENCES
Airflow
at
tW
Ho
Control Option Code: DO
VAV Cooling and VAV Heating, Dual Maximum
Flows
A decrease in room temperature modulates the A further decrease in room temperature
airflow from maximum to minimum setting (at modulates the airflow from minimum to
room thermostat setpoint).
alternate maximum setting and modulates the
hot water control valve to the open position.
O19
terminal unit accessories
DUAL DUCT
Airflow
Control Option Code: OO
VAV, No Mixing
The hot and cold duct controllers are set
independently for maximum airflow setting.
Both controls are set for zero minimum airflow.
100
demanding or unequal inlets are required, the
hot duct maximum can be adjusted for a lower
setting.
80
20
Hot and cold controls can be set for equal
maximum airflow. If heating loads are less
Equal Max. Flow Rates
Unequal Max. Flow Rates
Max.
60
40
Max.
Max.
t
Ho
C
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Model: PEDV
Control Option Code: OO
VAV with Mixing (Attenuator required)
Diagram shows unit with hot inlet and cold
total flow sensors. The hot control is still set
for zero minimum airflow. The unit minimum is
set on the cold inlet control. Unequal inlets are
available for the hot inlet.
Airflow
Maximum airflow can be independently
adjusted for equal or unequal settings. Mixing
begins when the cold airflow reaches minimum
airflow. When the hot airflow is greater than
the unit minimum, the cold damper is fully
closed. Optional cold inlet and hot total flow
sensors are available.
100
Max.
80
60
40
Max.
ld
O
d
ol
Max.
Co
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Control Sequences (continued)
Ho
20
t
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Models: PEDV, PMDV
Control Option Code: OO
O20
O20
100
Maximum airflow for the hot inlet is set equal
to unit minimum. Mixing begins when the cold
airflow reaches minimum airflow. When the
hot airflow is equal to the unit minimum, the
cold damper is fully closed. Optional cold inlet
and hot total flow sensors are available.
Max.
80
60
40
ld
Max.
Co
Ho
t
20
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Models: PEDV, PMDV
Models: PEDV, PMDC
Airflow
The cold control minimum and maximum are
set equal to total flow. The room thermostat
is connected to the hot control only. If the
optional cold inlet and hot total sensors are
selected, the mixing occurs between 8 and 13
psi thermostat pressure.
100
80
60
40
Max.
Max.
Co
ld
Control Option Code: OO
Constant Air Volume (Attenuator required)
Diagram shows unit with hot inlet and cold
total flow sensors. The hot control is set for
zero minimum airflow and maximum airflow is
equal to total airflow.
t
Ho
CONTROL SEQUENCES
VAV with Hot Maximum Equal to Unit
Minimum Airflow (Attenuator required)
Diagram shows unit with hot inlet and cold
total flow sensors. The hot control is still set
for zero minimum airflow. The unit minimum is
set on the cold inlet control. Unequal inlets are
available for the hot inlet.
Airflow
20
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Control Sequences (continued)
terminal unit accessories
Control Option Code: OO
Total Airflow
80
60
40
Plenum
Air
Max.
Pr
im
Ai ary
r
100
ate
tW
Ho
y
ar
im
Pr Air
r
Constant Volume Fan VAV Terminal with Hot
Water Heat
The unit fan delivers a constant airflow to the With a further decrease in room temperature,
space at all times. As the room temperature the room thermostat modulates the water coil
decreases, the primary air valve modulates valve to the open position.
the airflow from the maximum to the minimum
setting.
20
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Models: PTFS, PTQS, PFLS
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FAN POWERED
Control Option Code: OO
Total Airflow
80
Plenum
Air
Step 2
60
Step 1
40
y
ar
im
Pr Air
20
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
O
Thermostat Branch Pressure, (psi)
Models: PTFS, PTQS, PFLS
Control Option Code: OO
Airflow
Max.
100
60
y
ar
im
Pr Air
r
20
Plenum
Air
Pr
40
im
Ai ary
r
80
ate
tW
With a further decrease in room temperature,
the room thermostat energizes the unit fan and
the water coil valve modulates to the full open
position.
Ho
Variable Volume Fan VAV Terminal with Hot
Water Heat
As the room temperature decreases, the
primary airflow modulates from maximum
to minimum setting (at room thermostat
setpoint).
Max.
im
Ai ary
r
Step 3
100
Pr
Constant Volume Fan VAV Terminal with
Electric Heat
The unit fan delivers a constant airflow to the With a further decrease in room temperature,
space at all times. As the room temperature the electric heating coil is energized one step
decreases, the primary air valve modulates at a time.
the airflow from the maximum to the minimum
setting.
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Control Option Code: OO
Models: PTQP, PFLP
100
80
With a further decrease in room temperature,
the room thermostat energizes the unit fan and
the electric heating coil is energized one step
at a time.
Step 2
60
40
20
Max.
Plenum
Air
Step 1
Pr
im
Ai ary
r
Variable Volume Fan VAV Terminal with
Electric Heat
As the room temperature decreases, the
primary airflow modulates from the maximum
to the minimum setting (at room thermostat
setpoint).
Airflow
Step 3
y
ar
im
Pr Air
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
CONTROL SEQUENCES
Models: PTQP, PFLP
O21
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Control Sequences (continued)
terminal unit accessories
FAN POWERED
Control Option Code: AC
Constant Fan VAV Terminal with Night
Shutdown (NSD) PE
Day operation, main air ON. See the control Night operation, main air OFF, primary air fan
sequence outlined on page O21.
must be shut off. The unit fan remains off until
the main air is restored. Units with electric
heat must use reverse acting thermostats to
prevent heat operation when fan is off.
Airflow
Night Operation
Central System Off
100
80
60
No
Primary
Air
40
Fan Terminal Unit
Fan Off
20
RA
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Thermostat Branch Pressure, (psi)
Models: PTFS, PTQS, PFLS
Control Option Code: AE
Airflow
Central System Off
100
Plenum Air
80
NSB
Setpoint
l
l
na oi
tio g C
Op atin
He
60
40
20
RA
Thermostat Branch Pressure, (psi)
Control Option Code: AD
Constant Fan VAV Terminal with Night
Shutdown (NSD) Airflow Switch
Day operation, primary air handler ON. See
control sequence on page O21.
Airflow
100
Night operation, primary air to the unit is shut
off. The unit fan remains off until the primary
air is restored.
80
Night Operation
Central System Off
No
Primary
Air
60
40
20
Fan Shut Down
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Thermostat Branch Pressure, (psi)
Control Option Code: AF
Constant Fan VAV Terminal with Night
Setback (NSB) Airflow Switch
Day operation, primary air handler ON. See the Night operation, primary air OFF. The unit fan
control sequence on page O21.
remains off until the night setback thermostat
calls for heat. The unit fan energizes followed
by the water or electric heat.
Airflow
100
80
60
40
20
Central System Off
Plenum Air
l
l
na oi
tio g C
Op atin
He
CONTROL SEQUENCES
Models: PTFS, PTQP, PFLP
O22
O22
No
Primary
Air
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
NSB
Setpoint
O
Constant Fan VAV Terminal with Night
Setback (NSB) PEs
Day operation, main air ON. See the control Night operation, main air OFF, Primary air fan
sequence outlined on page O21.
must be shut off. The unit fan remains off until
the night setback thermostat calls for heat.
The unit fan energizes followed by the water
or electric heat. Units with electric heat must
use reverse acting thermostats to prevent heat
operation when fan is off.
Models: PTFS, PTQS, PFLS
No
Primary
Air
DA 0 1 2 3 4 5 6 7 8 9 10 11 12 13 1415
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
RA
Models: PTFS, PTQP, PFLP
Thermostat Branch Pressure, (psi)