Data Sheet for Product

Page 2 of 5 Siemens Industry Inc.
• Constant Volume in Occupied Mode and VAV in
Unoccupied Mode with Hot Water Reheat
(pneumatic output only)
Control algorithms are preprogrammed. The controller
is ready to operate after selecting the application. If
desired, the operator may adjust the air volume
setpoints in cfm (lps), differential flow, room
temperature setpoint and other parameters. The
controller is designed for operation and modification
without vendor assistance.
Hardware
Controller Board
The Room Pressurization Controllers consist of two
differential pressure transducers and either an
electronic or pneumatic controller assembly.
This controller provides all wiring terminations for
system and local communication and power. The cable
from the room sensor (purchased separately) connects
to the RJ-11 jack on the controller. All other
connections are screw terminations. The controller
assembly is mounted on a plastic track that mounts
directly on the terminal box. An optional enclosure
(P/N 550-002) protects the controller assembly.
Autozero Modules are available for those applications
where uninterrupted airflow is necessary.
The controller interfaces with the following external
devices:
• Averaging air velocity sensors provided by VAV
terminal unit manufacturers
• Floating control valve and damper actuators
• Room temperature sensor
• Room Pressurization Controller Pressure Mode
Switch
• Digital input devices (dry contacts from motion
sensors, motion detectors)
• Digital output device (fan, alarm indication)
Differential Pressure Transducer
The averaging air velocity sensors (provided by the
terminal box manufacturer) send an average air
velocity measurement of the duct air velocity to the
controller. The air velocity sensors connect to the
differential pressure transducers and measure the
average differential pressure. The measured value is
converted to actual airflow in cfm (lps) by the
controller.
Differential Pressure Transducer
Specifications
Temperature Range 32°F to 122°F (0°C to
50°C)
Measurement Range 0 fpm to 4000 fpm
(0 m/s to 20 m/s)
Measurement Resolution
±
4 fpm (
±
0.02 m/s)
Measurement Accuracy*
300 fpm to 4000 fpm
(1.5 m/s to 20 m/s)
±5% of actual reading
Repeatability
±
10 fpm (
±
0.05 m/s)
Maximum Distance of
Transducer from Air
Velocity Sensor
50 ft. (152 m)
*All specifications assume an unadjusted flow coefficient of 1.
Autozero Module
The optional Autozero Module (see Figure Autozero
Module) is required when continuous operation at
occupied flow is required for an area. The Autozero
Module is connected to the air velocity inlet ports of the
controller and provides periodic recalibration of the air
velocity transducer without changing air volume being
delivered to a room. This recalibration ensures long-
term precise airflow delivery.
Autozero Module Specifications
Power Consumption
.75 VA @ 24 Vac max.
Dimensions
2" W x 1.51" H x 1.89" D
(58 mm x 78 mm x 29 mm)
Weight
1.3 oz. (36.9 g)
Autozero Module.
Pneumatic Output Module
The Pneumatic Output Module contains the
transducers that provide the signal conversion from
electronic to pneumatic. Three modules are used per
controller. The gauge on the module provides a
readout of the pneumatic control signal. This can be
used during system start-up and troubleshooting.