ABB RET 54 Series, Техническое справочное руководство, общее

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1MRS755225 Transformer Terminal
Technical Reference Manual, General
RET 54_
57
Current transducers
When a current transducer is connected to the RTD/analog input, the SHUNT and
IN+ terminals are linked together as are the GND and IN- terminals. The incoming
current signal is connected to the IN+ terminal and the outgoing current signal to the
IN- terminal.
currtran_b
Fig. 5.1.9.6.-2 Principle diagram for the connection of current transducers
Voltage transducers
When a voltage transducer is connected to the RTD/analog input, the GND and IN-
terminals are linked together. The incoming voltage signal is connected to the IN+
terminal and the return voltage signal lead to the IN- terminal.
volttran_b
Fig. 5.1.9.6.-3 Principle diagram for the connection of voltage transducers
*) The GND terminals are galvanically isolated from the supply and enclosure of the
transformer terminal, but they are all connected to each other, i.e. they share the
same potential. When several inputs are connected to single-ended signal sources
that share a common ground, ground loops result if the connection GND <-> IN- is
done on every input. In this situation, the connection GND <-> IN- is done on only
one of the concerned RTD/analog inputs.
SHUNT
IN -
GND
I
*)
IN +
G
mA
DIFF
+
-
Transducer
amplifier
Sensor
SHUNT
IN -
GND
*)
IN +
G
mA
DIFF
+
-
Transducer
am plifier
Sensor