Instruction manual

SITRANS TW
94 A5E00054075-05
Hardware functions
3.6 External reference point compensation with reference
point terminal 7NG3092-8AV
3.6.1 Application and use
This serves as a reference point terminal in devices with the order designation
7NG3242-****0 in the thermocouple measuring mode with external reference point
compensation.
The basic accuracy of the reference point terminal is 0.5 °C (PT100 DIN IEC 751,
limit class B).
For applications with reduced accuracy requirements of the reference point
measurement (≤ 3 °C) the internal reference point compensation of the device
can also be used.
3.6.2 Connection and wiring
The reference point terminal and the thermocouple must be mounted on the input
plug (terminal 1-4) of the SITRANS TW as shown in figure 8.
The wiring of terminals 3 and 4 (chapter 6.4.2, page 130) in the circuit type
thermocouple with external thermocouple with external compensation is omitted. It is
already implemented in the reference point terminal.
Figure 8 Connection of reference point terminal and thermocouple
WARNING
In devices with "intrinsically safe" type of protection, make sure that the reference
point teminal 7NG3092-8AV and the input plug are mounted firmly in the blue
cable housing enclosed ex-factory before putting the devices into operation.
PT100 DIN IEC 751
1
2
3
4
+
-
1
2
3
4
Anschluss an Klemme 2
Anschluss an Klemme 3
Input plug Reference point terminal Thermocouple
(Terminal 1-4) 7NG3092-8AV
from SITRANS TW
7NG3242-****0
Connection to terminal 2
Connection to terminal 3