Connecting a 3-wire rtd – Rockwell Automation 1440-TTC06-00RE XM-362 Temperature Module User Manual
Page 35
Publication GMSI10-UM008D-EN-P - August 2010
27
Figure 2.13 Thermocouple to XM-361 wiring
Connecting a 3-Wire RTD
The XM-361 has variable gain circuitry that delivers the best possible range
and resolution for a given application. This is mostly determined by the
configuration’s input range. However, in the case of RTD lead wire detection,
these circuit settings are determined at power-up and are based off the actual
field wiring conditions. Therefore, any significant increase in field wiring
resistance that occurs after circuit power is applied may cause measurement
error.
Figures 2.14 to 2.19 show the wiring of 3-wire RTDs to the terminal base unit
of the XM-361 module.
TYPICAL WIRING FOR THERMOCOUPLES
TO XM-361 TEMPERATURE MODULE
30
29
IN 5+
IN 5 -
grounded thermocouple
grounded thermocouple
+
-
28
27
25
26
+
-
IN 6+
IN 6 -
within +/- 3V dc
-
+
ungrounded thermocouple
IN 4+
IN 4 -
37
38
Power
Supply
24V dc
+
-
within +/- 3V dc
ATTENTION
You may ground the cable shield at either end of the cable.
Do not ground the shield at both ends. Recommended
practice is to ground the cable shield at the XM-361
terminal base and not at the field device. Any convenient
Chassis terminal may be used (see Terminal Block
Assignments on page 18).
TIP
When the XM-361 module is configured for an RTD on
every channel, the cold junction temperature is determined
from an on-board sensor inside the module, NOT the
sensors inside the terminal block.