Siemens S5-155U System Manual page 392

The 460 Analog Input Module
Sensor,
Not Isolated
+
U E
-
+
U CM
-
Figure 9-7 Measuring Circuit without Equipotential Bonding Conductor for the 460 Analog Input Module
9 - 20
Example:
(Special case) The temperature of the busbar of an electroplating bath
is to be measured with an uninsulated thermocouple.
Analog Input Module
M +
MUX
Range
M -
Card for
4 Inputs
U CM
The potential of the busbar with respect to the reference potential of
the module is, for example, 24 V DC. A 460 analog input module with
isolated input is used (U
CM
bonding conductor must not be laid here because it would short-circuit
the busbar.
A
#
D
0 V Bus
= 60 V AC/75 V DC). An equipotential
C79000-B8576-C109-03
System Manual