Johnson Controls LX Series - Analog Inputs

LX Series Unit Ventilator Controller User's Guide 21
Analog Inputs
Analog inputs include current inputs with a range of 4 – 20 mA, and voltage inputs
with a range of 0 – 10 VDC.
4 to 20 mA Analog Input, Externally Supplied
Current inputs require a power supply either on the sensor or wired in series with
the sensor. To construct the current input, a 500-ohm 0.25-watt resistor is placed
across the Unit Ventilator Controller’s input terminals. See Figure 10 and
Figure 11.
Figure 10: Sensor Powered Analog Input
+
–
Resistor:
500
Ω −
¼
Watt
LX--UVL
4–20mA
Sensor
1
8
0
I
1
I
2
I
3
I
4
I
6
I
5
–
++++++
––
Internal 24
VDC
power supply
Controller source
output 4 – 20 mA
O=ohm
Figure 11: Externally Powered Analog Input
–
+
Resistor:
500
Ω −
¼
Watt
LX-UVL
4–20mA
–
+
24
VDC
Senso
r
1
8
0
I
1
I
2
I
3
I
4
I
6
I
5
–
++++++
––
O=ohm