1. Watt Estimation (W):
(Only applicable when voltage and current have pure sinusoidal waveform. This formula
can only be used for approximation. This formula doesn't consider the effect of harmonics,
spikes, surges, sag & swell )
R Phase watt = R Phase Voltage x R Phase Current x R Phase PF
Y Phase watt = Y Phase Voltage x Y Phase Current x Y Phase PF
B Phase watt = B Phase Voltage x B Phase Current x B Phase PF
Total Watt = Absolute value of R Phase watt + Absolute value of Y Phase watt + Absolute
value of B Phase watt
*if watt of a particular phase is showing negative, that means CT of that phase is
in reverse direction.
2. VAR Estimation:
(Only applicable when voltage and current have pure sinusoidal waveform. This formula
can only be used for approximation. This formula doesn't consider the effect of harmonics,
spikes, surges, sag & swell )
R Phase VAR = R Phase Voltage x R Phase Current x Sin(cos (R Phase PF))
Y Phase VAR = Y Phase Voltage x Y Phase Current x Sin(cos (R Phase PF))
B Phase VAR = B Phase Voltage x B Phase Current x Sin(cos (R Phase PF))
Total VAR = R Phase VAR + Y Phase VAR + B Phase VAR
3. VA Estimation
(Only applicable when voltage and current have pure sinusoidal waveform. This formula
can only be used for approximation. This formula doesn't consider the effect of harmonics,
spikes, surges, sag & swell )
R Phase VA = R Phase Voltage x R Phase Current
Y Phase VA = Y Phase Voltage x Y Phase Current
B Phase VA = B Phase Voltage x B Phase Current
Total VA =
4. Estimation of Wh (Active Energy):
To approximate the energy, apply a constant load to the meter. Say 2 Kilowatt. We can say if a
constant load of 2 KW flow via meter, then after 1-hour meter will calculate 2.000 KWh (i.e. unit). Formula
for same is shown below
KWh (for a specified time) = Kw x t , where t is time in hours
For ex:- If watt = 2Kilowatt and suppose we want to calculate energy for 30 mins (0.5Hours), then
Kwh (for 30 mins) = 2 * 0.5 = 1Kwh
(Similarly, KVAh and KVARh can be calculated)
4. List of parameters
6. Validating Parameters
Page 9
W + VAr
2
2
tot
tot
4. List of parameters
LCD
Series
ENERSOL
MFLR09
PROG
COM
Tot: 1.79KW
0002504.3KWh
To validate the energy, meter has
calibration LED, this LED blinks 1600
times per Kwh.
A Meter Test equipment read this pulses
via an optical sensor and calculate the
% error in energy.
Calibration LED
-1
-1
-1
