ABB REF 54 Series Technical Reference Manual page 50

5() B
50
)HHGHU 7HUPLQDO
Technical Reference Manual, General
&XUUHQW WUDQVGXFHUV
When a current transducer is connected to the RTD/analogue 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.
I
Sensor
Transducer
amplifier
)LJ   3ULQFLSOH GLDJUDP IRU WKH FRQQHFWLRQ RI FXUUHQW WUDQVGXFHUV
9ROWDJH WUDQVGXFHUV
When a voltage transducer is connected to the RTD/analogue 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.
Sensor
Transducer
amplifier
)LJ   3ULQFLSOH GLDJUDP IRU WKH FRQQHFWLRQ RI YROWDJH WUDQVGXFHUV
*) The GND terminals are galvanically isolated from the supply and enclosure of the
feeder 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/analogue inputs.
SHUNT
IN +
IN -
*)
GND
SHUNT
IN +
IN -
*)
GND
1MRS750527-MUM
G
mA
+
-
DIFF
currtran.CNV
G
mA
+
-
DIFF
volttran.CNV