Johnson Controls Penn System 450 Series User Manual

System 450™ Series Modular Control Systems with Standard Control Modules Technical Bulletin 17
Active and Passive Sensors
Each sensor/transducer hardwired to a System 450 control system is either an
active or passive sensor. Passive System 450 sensors are two-wire temperature
sensors that connect to one of the sensor input terminals and a common terminal
(C) only. Active sensors are three-wire humidity sensors and pressure transducers
that connect to one of the sensor input terminals, a common terminal, and a voltage
supply terminal (24V or 5V). The sensors and transducers have the following
requirements:
• Temperature sensors do not require a power source.
• Humidity sensors and differential air pressure transducers require 24 VAC
supply power and must be connected to the 24V terminal on the input terminal
block.
• P499 pressure transducers require a 5 VDC power source and must be
connected to the 5V terminal on the input terminal block.
On control modules with analog outputs, set the active/passive switches to ON for
passive temperature sensors and off for active humidity sensors.
On control modules with relay outputs, position the active/passive jumpers across
both pin terminals for passive temperature sensors and on one terminal for active
humidity and pressure sensors.
See System 450 Standard Control System Examples on page 27 for System 450
control system examples showing active/passive sensor jumper or switch settings.
Figure 6: Example Showing the Active/Passive Slide Switch Settings
on a Control Module with Analog Outputs
Figure 7: Example Showing the Active/Passive Jumper Positions
on a Control Module with Relay Outputs

Johnson Controls Penn System 450 Series Specifications

General

Brand	Johnson Controls
Model	Penn System 450 Series
Category	Control Systems
Language	English