WAGO-I/O-SYSTEM 750 XTR
Connect Devices 141
750-495/040-00x 3-Phase Power Measurement Module 690 V
Manual
Version 1.2.0
7.6.2.5 Measurement in Grounded Single-Phase Split-Phase Networks
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.
This measurement circuit is used in all grounded single-phase networks with an
additional center tap as a neutral conductor and with various types of load
connection.
The voltage measurement is performed via voltage transformers (VTs). Voltages
u
L1
and u
L3
are measured. From the measurement results, the I/O module first
calculates voltage u
L2
and then voltages U
L1
, U
L2
and U
L3
.
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.
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.