Mega MEg40+, Руководство пользователя

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Měřící Energetické Aparáty
8
The display of the instrument MEg40
+
shows total registers for the three-phase outlet.
The set of six registers for the individual phases are read by the user program. The phase
energy measurement is unimportant when it is measured in compensated MV networks
(MVL). Also in the recorder mode, only basic voltage, current, active power and voltage
event data and other user information appear on the display.
The basic measurement time is 10 periods. True RMS voltage, current, power and energy
values are measured continuously thanks to the phase lock look. As well, intervals to
record into the data memory are multiples of 10 periods. In this case, the sampling rate of
the measured voltages and currents is controlled by the phase locked loop derived from
the L1 phase voltage. The phase locked loop is active in the frequency range from 47.4 Hz
to 52.9 Hz. If the frequency of the L1 phase voltage is outside the frequency interval, the
sampling rate is set at 50.00 Hz.
Apparent powers, reactive powers and true power factors - PFs are calculated in MEg40
+
from true RMS voltages and currents and from active powers recorded during the
recording interval into the Flash data memory. The reactive power includes a deformation
power component. The universal energy meter MEg40
+
is designed for system, long-
term measurements. For this use, it has both usual synchronization of the internal time
through the oscillator frequency and synchronization of the internal time through the
network voltage frequency. This allows a unified analysis of events in the course and
also of long-term measurement campaigns. During a mains failure when internal time
synchronization through the network frequency is selected, the time is synchronized by
the internal oscillator with f = 50.00 Hz.
In the function of time course recording, the interval to record the measured values
can be set from 1.0 sec to 1 hour. Besides average values for the recording interval, it
is also possible to store maximum and minimum values of 0.2 sec (10 periods) in the
memory, which occurred in the recording interval. It is also possible to record RMS
values measured in the time when the recording interval is finished.
In order to protect the data memory from filling with clusters of numerous unimportant
events, e.g. in case of voltage oscillations near the specified limits, it is possible to record
events on a new page only after it is opened. It does not occur prior to the time defined
after the previous page is opened. It allows suppressing the possibility to fill the entire
data memory with unimportant data in case of clusters of events.
The standard size of the data memory of the instrument MEg40
+
is 4 MB. When average
values of all voltages, currents, active and reactive powers, and energies in the summary
set of six registers, and up to 50 events per 27 hr 05 min are recorded, it is possible to store
data for the time period of 577.3 days in the 4 MB memory with the recording interval
of 10 minutes. When the 16 MB memory card is used and the recording is selected for
all average values of measured quantities, maximum and minimum voltages, maximum
currents and active powers, energies in the set of six registers in the individual phases in