Etu Metering Function - Siemens WL Series Selection And Application Manuallines

Low Voltage Circuit Breaker
Electronic trip unit (ETU)
Power metering function
In addition to excellent protection capabilities, the WL ETU has
unparalleled power metering functionality. True RMS current
sensing for metering is obtained from the same current sensors
Measured value
Currents Ia, Ib, Ic, In
Ground-fault current Ig (measure with external Gnd transformer)
Line-to-line voltages Vab, Vbc, Vca
Line-to-neutral voltages Van, Vbn, Vcn
Average value of phase-to-phase voltages V L-L AVG
Apparent power kVA per phase
Total apparent power KVA
Active power kW per phase
Total active power kWtotal
Reactive power kvar
Total reactive power kvar
Power factor per phase
Power factor total
Demand of currents Ia, Ib, Ic
Average demand of 3-phase current
Demand kWD per phase
kW demand 3-phase active power kWD total
kVA demand kVA total
kVAR demand kVAR per phase
kVAR demand total
kWhr imported
kWhr exported
kVARh imported
kVARh exported
Frequency
Total harmonic distortions for current and voltage
Phase unbalance for current and voltage
Potential transformers (PTs) are required to step down the
supply voltage to a level that is suitable for local input
connection to the breaker. PTs must be wired to the secondary
connections of the breaker and configured for three-phase,
three-wire or three-phase, four-wire supply system. The
measured values can be sent to a central database for
future power analysis or consumption reports.
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used for overload protection. ETU power metering can measure
the following:
Value range Accuracy
30 ... 8000A ± 1%
100 ... 1200A ± 5%
80 ... 120% Vn ± 1%
80 ... 120% Vn ± 1%
80 ... 120% Vn ± 1%
13 ... 8000kVA ± 2%
13 ... 24000kVA ± 2%
-8000 ... 8000kW ± 3% (power factor > 0.6)
-24000 ... 24000kVA ± 3% (power factor > 0.6)
-6400 ... 6400kvar ± 4% (power factor > 0.6)
-20000 ... 20000kvar ± 4% (power factor > 0.6)
-0.6 ... 1 ... 0.6 ± 0.04
-0.6 ... 1 ... 0.6 ± 0.04
30 ... 8000A ± 1%
30 ... 8000A ± 1%
13 ... 8000kW ± 3% (power factor > 0.6)
13 ... 8000kW ± 3% (power factor > 0.6)
13 ... 8000kVA ± 2%
13 ... 8000kVA ± 2%
-24000 ... 24000kvar ± 4% (power factor > 0.6)
1 ... 10000MWh ± 2%
1 ... 10000MWh ± 2%
1 ... 10000Mvarh ± 4%
1 ... 10000Mvarh ± 4%
15 ... 440 Hz ± 0.1 Hz
2 ... 100% ± 3% from the meas. range up to the 29th harmonic
2 ... 150% ± 1%
Event log
The event log is very extensive. Information regarding the
list of events can be found in the WL operation manual or
communication guide. Some of the event log categories are:
• Warnings
• Trip Logs
• Set-points
• Maintenance Detail
• CubicleBus Conditions
• Waveform Displays
WL Circuit Breaker selection and application guide