ABB 615 Series ANSI, Technical Manual

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Section 3
1MAC050144-MB C
Basic functions
78 615 series ANSI
Technical Manual
3.10.12 RTD/mA input connection
RTD inputs can be used with 2-wire or 3-wire connection with common ground.
Whenusing the 3-wire connection, it is important that all three wires connecting the
sensorare symmetrical, that is, the wires are of same type and length. The
graphicalrepresentation of the RTD and milli-ampere input connections can be found
under thesection "RTD/mA card variants".
3.10.13 RTD/mA card variants
The two variants of RTD cards available are, 6RTD/2mA card and 2RTD/1mA card.The
features are similar in both the cards.
3.10.13.1 6RTD/2mA card
This card accepts 2 milli ampere inputs and 6 inputs from the RTD sensors. The inputs
1
and
2
are used for current measurement, whereas inputs from
3
to
8
are used for resistance
type of measurements.
RTD/mA input connections
The examples of three-wire and two-wire connections of resistance and temperature
sensors to the 6RTD/2mA board are shown:
Figure 12: Three RTD and resistance sensors connected according to the
three-wire connection for 6RTD/2mA card