SCHEDULE TYPE:
PROJECT:
ENGINEER:
CONTRACTOR:
DATE
B SERIES
SUPERSEDES DRAWING NO.
10 - 18 - 07
3500
12 - 2 - 02
35SCD-1P3
PNEUMATIC CONTROL
FAN POWERED TERMINAL UNIT • SERIES FLOW
CONSTANT VOLUME • PRESSURE INDEPENDENT
MODELS: 35S, 35SST, 37S AND 37SST 1P3
Nailor Industries Inc. reserves the right to change any information concerning product or pricing without notice.
Dimensions are in inches (mm).
CONTROL SEQUENCE 1P3 • VAV COOLING (CONTINUOUS
OPERATION) • DA/NO • 3000 CONTROLLER
Sequence of Operation:
The unit fan will deliver a constant volume to the space at all times. With space
temperature at set point, unit delivers minimum cooling airflow and maximum
induced plenum air.
On a rise in space temperature, the thermostat regulates the controller to
increase primary airflow. As more cold air is supplied to the fan section, less
warm air is induced from the ceiling plenum.
When the space temperature is warm, the primary air damper is controlling at
the maximum airflow setting (usually the same as the fan volume setting and
no plenum air is induced).
As the space temperature decreases, the damper modulates back towards
the minimum airflow setting and as less cold air is supplied to the fan section,
more warm air is induced. If room temperature continues to drop, minimum
primary airflow is maintained.
Primary airflow is held constant in accordance with thermostat demand. Any
changes in volume due to static pressure fluctuations are sensed and
compensated for, resulting in pressure independent control.
Note:
Constant volume series terminal fans should be electrically or pneumatically
field interlocked with the central fan system, to prevent backflow of primary
air into the ceiling plenum and to prevent possible backward rotation of the
terminal fan.
MCP-8030
ACTUATOR
(8 – 10 PSI)
NORMALLY OPEN
DAMPER
BALANCING
TEES
DIAMOND
FLOW
SENSOR
AIRFLOW
RESET START POINT
FACTORY SET
@ 8 PSI
RESET SPAN
FACTORY SET
@ 5 PSI
CSC-3011
RESET CONTROLLER
FACTORY WIRING/ PIPING
FIELD PIPING
M B
MAIN AIR
20 PSI
M
B
M
H
L
T
G
DAMPER
NC
NO
KREUTER
SETTING
MUST BE
N. O.
LINE
VOLTAGE
TOGGLE
DISCONNECT
SWITCH
(OPTIONAL)
SPEED
CONTROLLER
CAPACITOR
N
H
FAN
MOTOR
HI LO
DIRECT ACTING
2-PIPE THERMOSTAT
(OPTIONAL OR BY OTHERS)
TOTAL AIRFLOW
MAX.
CLG.
MIN.
PRIM
AR
Y AIR
THERMOSTAT OUTPUT PRESSURE, PSI
SPACE TEMPERATURE INCREASE
INDUCED AIR
3
0
8
13
15
AIRFLO
W INCREASE
100
80
60
40
20
0
Options:
Two Pipe Thermostat (Vertical Mount.
Includes backing plate for 2" x 4" electrical box).
❑
CTC-1621-103 °F scale plate
❑
CTC-1621-113 °C scale plate
