Rockwell Automation 1771-IR Series D RTD Input Module User Manual - Manual (Page 67)

2 and 4–Wire RTD Sensors E–3
Publication 1771Ć6.5.129 - March 2000
The illustration below shows how to connect 4–wire sensors to the
field wiring arm of the RTD Input module. A 4–wire sensor has two
pairs of leads; one pair for each resistor junction. One wire of the 4 is
not used (it does not matter which one). This leaves 3 wires – one
pair and one single wire. You must connect the single wire to the
terminal marked ”A”. You connect the remaining pair of wires to
terminals ”B” and ”C”. It doesn’t matter which wire of the pair
connects to terminal ”B” and which wire connects to terminal ”C” so
long as all 3 wires are the same AWG gauge.
Connecting a 4–Wire Sensor to the Field Wiring Arm
18
16
14
12
10
8
6
4
2
C
B
A
C
B
A
C
B
A
C
B
A
C
B
A
C
B
A
RTD
Ground
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Terminal
Identification
Chassis
Leave 1 lead open
Single lead connects to terminal A
12935-I
Note: In this illustration:
Terminal A is the 1mA excitation sourcing current
Terminal B is the lead compensation sense input
Terminal C is common
Connecting 4-Wire
Sensors