MI 2892 Power Master
Operating the instrument
44
GREEN colour – represents part of conductor cross section (wire) used
for active energy transfer (Ep)
RED colour – represents part of conductor cross section (wire) used for
fundamental reactive energy transfer (Eq)
BLUE colour – represents part of conductor cross section (wire) used for
nonfundamental (harmonic) apparent energy transfer (S
ɴ
)
BROWN colour – represents unbalanced power (S
U
) portion flowing in
polyphase system in respect to phase power flow.
Date
End time of shown interval.
Max. Power
Demand
Shows three intervals where measured fundamental active power was maximal.
According to the selected channel (key: F3), and VIEW (key: F1) consumed phase and
total fundamental active power is shown (Pfund
1
+
, Pfund
2
+
, Pfund
3
+
, P
+
tot
+
) or generated
phase and total fundamental active power is shown (Pfund
1
-
, Pfund
2
-
, Pfund
3
-
, P
+
tot
-
)
Table 3.21: Keys in Energy (TREND) screens
VIEW
Switches between Consumed (+) and Generated (-) energy view.
TOT
LAST MAX
Shows parameters for complete record duration
TOT
LAST
MAX
Shows parameters for last (complete) recorded interval
TOT LAST
MAX
Shows parameters for interval, where active energy was maximal
1
2 3
T
Shows energy records for phase L1.
1
2
3
T
Shows energy records for phase L2.
1
2
3
T
Shows energy records for phase L3.
1
2 3
T
Shows all phases energy records.
1
2 3
T
Shows energy records for Totals.
METER
Switches to METER view.
TREND
Switches to TREND view.
EFF
Switches to EFFICIENCY view.
Returns to the “MEASUREMENTS” submenu.
3.8
Harmonics / interharmonics
Harmonics presents voltage and current signals as a sum of sinusoids of power frequency and its integer
multiples. Sinusoidal wave with frequency k-times higher than fundamental (k is an integer) is called
harmonic wave and is denoted with amplitude and a phase shift (phase angle) to a fundamental
frequency signal. If a signal decomposition with Fourier transformation results with presence of a
frequency that is not integer multiple of fundamental, this frequency is called interharmonic frequency
and component with such frequency is called interharmonic. See 5.1.8 for details.
3.8.1
Meter
By entering HARMONICS option from Measurements submenu the tabular HARMONICS (METER) screen
is shown (see figure below). In this screens voltage and current harmonics or interharmonics and THD
are shown.
F1
F2
F3
F4
