Reactive Power And Energy Calculation; Connection; Setting Of Current And Voltage Ratios; Used Voltage And Current Range (Mc350, Mc350H And Mc330 Only) - Iskra MC320 User Manual

SETTINGS
Reactive power and energy calculation
User can select between two different principles of reactive power and energy calculation:
Standard method:
With this method a reactive power and energy are calculated based on assumption that all power (energy) that
is not active is reactive.
2 2 2
Q = S ‐ P
This means also that all higher harmonics (out of phase with base harmonic) will be measured as reactive power
(energy).
Delayed current method:
With this method, reactive power (energy) is calculated by multiplication of voltage samples and delayed current
samples (see chapter Equations on page 72):
Q = U × I|
+90°
With this method, reactive power (energy) represents only true reactive component of apparent power (energy).
Connection
PLEASE NOTE
Settings of connections shall reflect actual state otherwise measurements are not valid.
Connection
When connection is selected, load connection and the supported measurements are defined (see chapter Survey
of supported measurements regarding Connection mode on page 21).
Main menu  Settings  Connection  Connection mode
Setting of current and voltage ratios
Before setting current and voltage ratios it is necessary to be familiar with the conditions in which device will be
used. All other measurements and calculations depend on these settings. Up to five decimal places can be set
(up / down). To set decimal point and prefix (up / down) position the cursor (left /right) to last (empty) place or
the decimal point.
Settings range VT primary
Maximal value 1638.3 kV
Minimal value
Main menu  Settings  Connection  VT primary / VT secondary / CT primary / CT secondary
Used voltage and current range (MC350, MC350H and MC330 only)
Setting of the range is connected with all settings of alarms, where 100% represents 500 V and 5A. In case of
subsequent change of the range, alarms settings shall be correspondingly changed, as well.
Nominal frequency (MC350, MC350H and MC330 only)
A valid frequency measurement is within the range of nominal frequency ±32 Hz. This setting is used for alarms
only.
Measuring centres – MC320, MC330, MC350 & MC350H ‐ User's Manual
VT secondary
13383 V
0.1 V 1 mV
CT primary CT secondary
1638.3 kA 13383 A
0.1 A 1 mA
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