Measurement In Ungrounded Single-Phase Split-Phase Networks - WAGO 750-495/040-00 Series Manual

128 Connect Devices
7.6.1.10

Measurement in Ungrounded 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 ungrounded 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 and u
L1 L3
calculates voltage u
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.
Always use voltage transformers with basic insulation and ground the
module-side N connection
In ungrounded single-phase split-phase networks with a neutral conductor,
always use voltage transformers with at least basic insulation and ground the
module-side N connection.
Otherwise, touch-proof protection from the system may no longer be given in the
event of a fault. This can cause electric shock or burns.
The nominal input voltage is:
- u = 200 V
LN
Voltage" setting
- u = 400 V
LN
Voltage" setting
Parameter 47 is used for the setting.
To avoid erroneous measured values for the unused phase, the unused voltage
input L2 can be connected to the N connection.
Manual
Version 1.2.0
750-495/040-00x 3-Phase Power Measurement Module 690 V
are measured. From the measurement results, the I/O module first
and then voltages U
L2
if a voltage ≤ 120 V
RMS
if a voltage > 120 V
RMS
WAGO-I/O-SYSTEM 750 XTR
, U and U .
L1 L2 L3
is parameterized for the "Secondary
RMS
is parameterized for the "Secondary
RMS