WAGO-I/O-SYSTEM 750 XTR
Connect Devices 137
750-495/040-00x 3-Phase Power Measurement Module 690 V
Manual
Version 1.2.0
7.6.2.3 Measurement of Multiple Grounded Single-Phase Networks with a
Common Neutral Conductor
The “4-Wire Wye” (“4-W”) topology is available in WAGO-I/O-Check for voltage
measurement.
This topology is fixed in firmware versions 04 and below and selectable in
WAGO-I/O-
Check
in firmware versions 05 and above.
The voltage transformer ratio can be parameterized in firmware versions 05 and
above and WAGO-I/O-
Check
versions IO-3.18.1 (CS0609) and above.
Up to 3 grounded single-phase networks with a common neutral conductor can
be connected to the I/O module.
The measurement circuit basically corresponds to the “Grounded 3-Phase
Network with Neutral Conductor for Power Measurement and Voltage
Measurement on 3 Line Conductors for U
LN
> 400 V
RMS
and u
LN
≤
400 V
RMS
”
connection schematic,
Voltage measurement is performed via voltage transformers (VTs).
The current measurement is performed via current transformers (CTs) or
Rogowski Coils.
The measured values of unconnected voltage and current measurement inputs
have no significance.
However, for voltage measurement, the voltage to measure must be connected
to each voltage input of the I/O module. A voltage connected to a terminal cannot
be passed on for the calculation of the other phases on the firmware side.
The voltage transformer ratio and current transformer ratio must be taken into
account for the correct calculation of all values in the process image.
The nominal input voltage is:
- u
LN
= 200 V
RMS
if a voltage ≤
120 V
RMS
is parameterized for the “Secondary
Voltage” setting
- u
LN
= 400 V
RMS
if a voltage > 120 V
RMS
is parameterized for the “Secondary
Voltage” setting
Parameter 47 is used for the setting.
For optional measurement of the neutral conductor current, ensure that it does
not exceed the maximum current of the I/O module. If applicable, use a current
transformer with a higher transformation ratio.