Project Planning Manual
SIPART DR20
2L
3
1
2
4
R
L4
6DR2800-8P
K L M
+
-
0
1
2
3
4
5
1 2 3 4 5 6 7
+
R
0
Ι
U
C
B
A
D
E
F
U
REF
∆
R
i
m
Pt100
R
L1
3L
3
1
2
4
R
L4
Pt100
R
L1
4L
3
1
2
4
R
L4
Pt100
R
L1
R
L3
R
L3
R
L2
B = C, E = F
R
0
= R
tA
A = B, D = E
R
0
= R
tA
+
R
L4
- R
L1
A = B, D = E
R
0
= R
tA
+
R
L1
+ R
L4
i
m
=
⎯⎯⎯
0.1 V
∆
R
P
Fig. 5/7
Wiring of module 6DR2800-8P for Pt 100 resistance thermometer
6DR2800-8T
see wiring diagram, Fig. 5/8
All common types of
thermocouples
and
mV sources
can be connected to this module, As the
low-drift input amplifier has a very high common-mode suppression, a DC or low-frequency AC
voltage up to
±
10 V may occur between the transmitter and the controller ground. Thus non-
isolated thermocouples (welded-on, earthed in undefined manner) can also be connected if two
SIPART DR20 controllers are provided with a thermocouple input and connected together via the
ground lead. If this is not the case, it is recommendable to connect terminal 3 to M (terminal 6 of
standard controller). Electrical isolation is then provided via the mains transformer. Fine adjustment
with a mV transmitter must also be carried out with this connection.
Thermocouples can be connected either via thermostats/compensation boxes or directly to the
internal cold junction via the temperature sensor fitted on the terminal block (terminals 1 and 2).
This compensation circuit is referred to 0 °C and only necessary for thermocouples with internal
cold junction. Only in this case the type of thermocouple must be selected by jumper marshalling
on the module.
The jumper marshalling must be left open (connect one pole to E) in the case of thermocouple
type B, thermocouples with an external cold junction or with mV signals which do not come from a
thermocouple.
78