Siemens SENTRON VL Series System Manual page 44

3WL air circuit breakers
3.3 Metering functions
Mounting
The metering function PLUS can be operated with all switches with ETU45B and ETU76B. If
the metering function PLUS is ordered together with the circuit breaker using the short code
"Z=F05", it is already built-in and ready for operation. The metering function PLUS can be
retrofitted at any time if the switch is fitted with one of the above-listed trip units. The
metering function PLUS is screwed onto the trip unit and the CubicleBUS cables are clicked
into place.
NOTICE
If retrofitting is carried out by the customer, the metering function PLUS will not be
calibrated together with the trip unit. Siemens accepts no liability for the accuracy
information in the table "Metering function PLUS - measured values for communication".
Harmonic analysis
The metering function PLUS samples the applied currents and the voltage, saves the
measured values, and carries out a fast Fourier transformation. The result is the percentage
distribution of the harmonic oscillations up to the 29th harmonic. The determined values are
made available via the CubicleBUS and can be displayed via Switch ES Power (see Chapter
), and saved for later diagnostics as an Excel-compatible "*.csv" file. In the case of the
ETU76B trip unit, the measured and calculated values can also be shown on the display.
Figure 3-9
44
Harmonics analysis of the metering function PLUS
3WL/3VL circuit breakers with communication capability - PROFIBUS
System Manual, 03/2011, A5E01051353-02