Mega MEg40+ Manual - page 13
13
Universal Energy Meter MEg40
+
When you select the item Instrument parameters, the instrument MEg40
+
displays
the basic information about the instrument, i.e. serial number, control program version
- FW, date and time of the internal clock and capacity of the Flash data memory of
the instrument. When the 16 MB memory card is inserted, the capacity of this card is
displayed. To return to the previous selection, use the button End.
When you set and select the main item Maximum currents, the instrument MEg40
+
displays maximum currents for the measurement interval for each phase and maximum
value of the sum of phase currents measured by the instrument from the programmed
start. As well times and dates are displayed, when the individual maximums occurred.
After the item Recorder is selected, information about the course of function is displayed.
When the record is not active, the message Record completed will appear on the line
Status
or the message Recording when the function Recorder is set. When the function
Recorder is programmed, also additional lines appear on the display including the
recording start time, i.e. hour, minute, second and date, and information that measured
data are stored in the memory, i.e. linear or circular memory, including information
about the interval when the measured data are stored into the memory.
After you select the item Check of wiring, four functions run automatically to check the
wiring of connected measuring circuits for correctness. They are the following functions:
• voltage connection check,
• phase sequence check,
• current connection check,
• phase assignment check..
The used checking procedure may not detect double and multiple errors in the wiring
and may not be effective even when the wiring is correct, if there is a big voltage or
current unbalance or power factors and currents are small. The correct result of the
checking function is indicated by OK. In case of an ambiguous result, the quantities will
be displayed, because of which it was impossible to decide about the correct wiring, and
after the button TEST is enabled, the result is marked with the question mark. A wiring
error is indicated by the word Error.
To check voltage connections, phase and delta voltages are checked. This function
assumes phase voltages higher than 0.75 Unom. If it is found out that one, two or all
three voltages are not connected, the message „Voltage connection error“ will be displayed
and the evaluated delta voltages, from which the disconnected voltage can be derived. The
Voltage connection checking
function may not be effective to check the common wire
for connection.
The following function checks the phase sequence. The check result is the message Phase
sequence 123 (clockwise) or Phase sequence 132 (counter-clockwise).