Schneider Electric PM820 Marine Instruments User Manual


 
© 2011 Schneider Electric. All Rights Reserved.
PowerLogic
TM
Series 800 Power Meter 63230-500-225A2
Appendix C—Using the Command Interface 3/2011
90
Setting Up Individual Harmonic Calculations
The PM810 with a PM810LOG can perform up to the 31st harmonic magnitude and angle
calculations for each metered value and for each residual value. The Power Meter can
perform harmonic magnitude and angle calculations for each metered value and for each
residual value. The harmonic magnitude for current and voltage can be formatted as either
a percentage of the fundamental (THD), as a percentage of the rms values (thd), or rms.
The harmonic magnitude and angles are stored in a set of registers: 13,200–14,608. During
the time that the power meter is refreshing harmonic data, the power meter posts a value of
0 in register 3246. When the set of harmonic registers is updated with new data, the power
meter posts a value of 1 in register 3246. The power meter can be configured to hold the
values in these registers for up to 60 metering update cycles once the data processing is
complete.
The power meter has three operating modes for harmonic data processing: disabled,
magnitude only, and magnitude and angles. Because of the extra processing time
necessary to perform these calculations, the factory default operating mode is magnitudes
only.
To configure the harmonic data processing, write to the registers described in Table C–4:
Refer to “Register List Access” on page 79 for instructions on accessing the complete register list.
Table C–4: Registers for Harmonic Calculations
Reg No. Value Description
3240 0, 1, 2
Harmonic processing;
0 = disabled
1 = magnitudes only enabled
2 = magnitudes and angles enabled
3241 0, 1, 2
Harmonic magnitude formatting for voltage;
0 = % of fundamental (default)
1 = % of rms
2 = rms
3242 0, 1, 2
Harmonic magnitude formatting for current;
0 = % of fundamental (default)
1 = % of rms
2 = rms
3243 10–60 seconds
This register shows the harmonics refresh interval
(default is 30 seconds).
3244 0–60 seconds
This register shows the time remaining before the
next harmonic data update.
3245 0,1
This register indicates whether harmonic data
processing is complete:
0 = processing incomplete
1 = processing complete