17-1
IM DL850E-01EN
17 Power Math
Digital Monitor Mode (Digital Monitor Mode)
Only the numeric monitor of the selected group is displayed on the screen.
Display Group: Only the numeric monitor of the group selected with Select Display Gr of Display Groups
(DISPLAY) is displayed on the screen.
: Only the numeric monitor of the power analysis measurement functions is displayed on the screen.
: Only the numeric monitor of the harmonic analysis measurement functions is displayed on the screen.
Power Analysis (Power)
The voltage and current measured on separate input channels can be used as math sources to calculate various
power parameters for power analysis. This is a feature available on the /G5 option.
• Power analysis can be performed when any of the following modules is installed in a slot other than slot 7.
701250 (HS10M12), 701251 (HS1M16), 701255 (NONISO_10M12), 701267 (HV (with RMS)),
720210 (HS100M12), 701261 (UNIVERSAL), 701262 (UNIVERSAL (AAF)), 701265 (TEMP/HPV),
701275 (ACCL/VOLT)
• Channels that can be used for power analysis are CH13 and CH14. Power analysis results are output to the
subchannels of CH13 and CH14.
The number of calculations performed in one analysis is equal to the total number of subchannels of CH13
and CH14.
• There can be up to 126 power analysis parameters that can be calculated. The number of parameters varies
depending on the number of systems to be analyzed and wiring system. For details, see the appendix.
• Power analysis conditions can be changed even during waveform acquisition. However, if you change the
conditions, the measurement count (waveform acquisition count) is reset.
The measurement count is displayed in the lower left of the screen.
• The analysis result waveform can be used as a trigger source, but it cannot be used as a real time math
source.
• Power analysis can be performed on two systems. This allows power efficiency and motor efficiency to be
calculated.
Measurement Functions
The various physical quantities such as rms voltage, average current, power, and phase difference that the
DL850E/DL850EV measures and displays are called measurement functions. Each physical quantity is
displayed with a corresponding symbol.
For example, Urms represents the true rms voltage.
Source Channels
The channels that receive the pair of voltage and current signals to be measured are called source channels.
There are three source channel numbers: 1, 2, and 3. The DL850E/DL850EV displays a source channel
number after the measurement function symbol to indicate which source channel corresponds to the
displayed numeric data.
For example, Urms1 represents the true rms voltage of source channel 1.
The channels that can be used as source channels are those of the modules that can perform power analysis
(indicated above).
Wiring Unit
Wiring Unit
refers to a group of two or three input source channels with the same wiring system used to
measure three-phase power.
Wiring unit is represented with the symbol Σ. Measurement functions for wiring units are called Σ functions.
For example, UrmsΣ represents the true rms value of the average of the voltages measured on the input
source channels assigned to wiring unit Σ.