ABB AC500 V3 - Connection of resistance thermometers in 2-wire configuration; Connection of resistance thermometers in 3-wire configuration

Connection of resistance thermometers in 2-wire configuration
When resistance thermometers (Pt100, Pt1000, Ni1000) are used, a constant current must flow
through them to build the necessary voltage drop for the evaluation. For this, the module AI523
provides a constant current source which is multiplexed over the 8 analog channels.
UP
ZP
1.0
I0-
1.1
I1-
1.8
UP
1.9
ZP
PTC
2.0
I0+
2.1
I1+
2.8
UP
2.9
ZP
Pt100
Pt1000
Ni1000
Fig. 25: Connection example
The following measuring ranges can be configured Ä Chapter 1.6.2.2.2.6 “Parameterization”
on page 444.
Pt100 -50 °C...+70 °C 2-wire configuration, one
channel used
Pt100 -50 °C...+400 °C 2-wire configuration, one
channel used
Pt1000 -50 °C...+400 °C 2-wire configuration, one
channel used
Ni1000 -50 °C...+150 °C 2-wire configuration, one
channel used
The function of the LEDs is described under Displays Ä Chapter 1.6.2.2.2.7 “Diagnosis”
on page 447.
The module AI523 performs a linearization of the resistance characteristic.
In order to avoid error messages from unused analog input channels, it is useful to configure
them as "unused".
Connection of resistance thermometers in 3-wire configuration
When resistance thermometers (Pt100, Pt1000, Ni1000) are used, a constant current must flow
through them to build the necessary voltage drop for the evaluation. For this, the module AI523
provides a constant current source which is multiplexed over the max. 8 (depending on the
configuration) analog channels.
Device specifications
I/O modules > Analog I/O modules
2022/01/31 3ADR010278, 3, en_US 437