Product Overview

System 450™ Series Modular Controls Product Bulletin 3
System 450 Applications
You can create a wide variety of custom,
application-specific control systems with System 450
modules. The following are some common control
application examples:
• temperature control
• pressure control
• humidity control
• multipurpose control
• reset and setback control
• high input-signal selection
• differential control
Temperature Control
Temperature control application examples include:
• heating and/or cooling control
• heating and cooling control with deadband
• boiler temperature stage control
• boiler circulating pump control
• chilled water temperature stage control
• discharge air temperature control
• modulating damper or valve control
Pressure Control
Pressure control application examples include:
• refrigeration compressor capacity control
• staged SPDT condenser fan control
• two-speed fan motor control
• floating pressure control of an actuator
• constant static pressure or air velocity control
• relief damper building pressurization control
• relief fan building pressurization control
• Electronically Commutated (EC) motor control
(C450CPW-100 model)
Humidity Control
Humidity control examples include:
• humidification/dehumidification control
• staged SPDT humidity control
Multipurpose Control
Multipurpose application examples include:
• temperature and pressure based refrigeration rack
control
• temperature and humidity control for a wine cellar
or greenhouse
• temperature, static pressure, and humidity for a
clean room application
Reset and Setback Control
Reset and setback control applications include:
• temperature control for single stage or
multi-stage (up to ten stages) boilers with or
without load balancing (equal runtime hours)
• humidity reset and temperature control for
natatorium/swimming pool zones
High Input Signal Selection
Beginning with firmware Version 2.00, standard System
450 control modules include the High Input-Signal
Selection control capability.
The High Input-Signal Selection feature enables a
System 450 control system to monitor a condition
(temperature, pressure, or humidity) with two or three
sensors (of the same type) and control relay and/or
analog outputs based on the highest condition value
sensed by the two or three referenced sensors.
High Input Signal Selection examples include:
• fan-staging control on multi-circuit condensers
• fan speed control on multi-circuit condensers
Differential Control
Beginning with Version 2.00 firmware, standard System
450 control modules also include Differential Control
capability.
Differential control is used to monitor and maintain a
given difference in a condition (temperature, pressure,
or humidity) between two sensor points within a
system, process, or space.
The Differential Control feature enables a System 450
control system to monitor the temperature, pressure, or
humidity differential between two sensors of the same
type (Sn-1 and Sn-2) and control relay and/or analog
outputs based on the sensed differential value relative
to user-selected differential values.
Differential Control application examples include:
• solar heating systems
• pump pressure-drop monitoring and control
• fluid filter pressure-drop monitoring