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Useful Information
Dimensions
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End of Programming
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The variables measured by the instrument are
correct if the polarities of the inputs have been
observed (as shown in the figure below); if not,
measuring and retransmission errors may occur due to
the wrong direction of the current flowing in the primary
/ secondary of the connected current transformer.
Example 2 “Use of digital filter”:
it’s necessary to stabilize
the displayed value of the VL1-N variable that varies between
222V and 228V. The parameters of the digital filter are to be
set as follows:
•
rnG: the variable varies within the average value, the
amplitude of which is equal to ±1.3% of the variable’s rated
value, calculated as follows:
(228-222)/2=±3V, then ±3*100/231V=±1.3%, where 231V
is the phase-neutral rated value of a 400V input range. The
“range” parameter, that corresponds to the action range of
the digital filter, is set at a value which is slightly higher than
the percentage amplitude of the fluctuation: e.g. 2%.
•
CoE: if the new value acquired by the instrument is with-
in the filter’s action range, then the new displayed value is cal-
culated by summing algebraically to the previous value the
variation divided by the filtering coefficient. As a conse-
quence, a value which is higher than this coefficient implies a
longer settling time and therefore improves the stability. The
latter can also be improved by increasing the filtering coeffi-
cient: the admitted values are within 1 and 16. Enter the value
in consecutive attempts until you reach the desired stability.
