Johnson Controls System 450 Series Installation Instructions Manual page 3

Active/Passive Sensor Jumpers
L2
L1
L2
L1
Note: In 120 VAC applications, L1 must be the Hot lead
Figure 3: Example System 450 Heat/Cool System with Condenser Fan Speed Control
Table 1: System 450 Terminal Wiring Information
Label Terminal Function
24V Accepts 24 VAC supply power, when a C450YNN power module is not connected,
and provides power terminal for 24 VAC (humidity) sensors.
5V Provides 5 VDC power for active sensors.
Sn-1, Sn-2, Accepts passive or active (0-5 VDC) input signals from sensors.
Sn-3
Note: You must position the Active/Passive Sensor Jumper (Figure 3 and
Figure 6) correctly for each sensor in your control system before operating the
system. See Setting Active/Passive Sensor Jumpers for more information.
C Provide low-voltage Common connections for 24 VAC power and passive or active
(Three sensors connected to the 5V, Sn1, Sn2, and Sn3 terminals.
Terminals)
Note: The three C terminals are connected internally and can be connected to
ground in the field.
LNC1, LNC2 Connects control circuit to the Normally Close (NC) contact on the SPDT relay.
LNO1, LNO2 Connects control circuit to the Normally Open (NO) contact on the SPDT relay.
LC1, LC2
Connects line (power) to Common (C) on the SPDT
1. See Internal SPDT Relay insert in Figure 2 for more System 450 relay contact and terminal information. See Technical
Specifications for SPDT relay electrical ratings.
System 450™ Series Control Modules with Relay Outputs Installation Instructions
and L2 must be the Neutral/Common lead.
Sn-1
Sn-2
Sn-3
L1 L2
1
relay.
0-10 VDC or
4-20 mA
Analog Output
Signal
Wire Sizes
2
0.08 mm to 1.5 mm
28 AWG to 16 AWG
2
0.08 mm to 2.5 mm
28 AWG to 14 AWG
2
2
3