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The function outputs the START, TRIP and BLOCKED signals which can be used for direct I/O
controlling and user logic programming. The function generates general time-stamped ON/OFF events
to the common event buffer from each of the three (3) output signals. In the instant operating mode the
function outputs START and TRIP events simultaneously with an equivalent time stamp. The time stamp
resolution is 1 ms. The function also provides a resettable cumulative counter for the START, TRIP and
BLOCKED events.
The following figure presents a simplified function block diagram of the overvoltage function.
Figure. 5.3.10 - 121. Simplified function block diagram of the U> function.
Measured input
The function block uses analog voltage measurement values. The monitored magnitudes are equal to
RMS values. A -20 ms averaged value of the selected magnitude is used for pre-fault data registering.
Table. 5.3.10 - 101. Measurement inputs of the the U> function.
Signal
Description
Time base
U
L12
RMS
RMS measurement of voltage U
L12
/V
5 ms
U
L23
RMS
RMS measurement of voltage U
L23
/V
5 ms
U
L31
RMS
RMS measurement of voltage U
L31
/V
5 ms
U
L1
RMS
RMS measurement of voltage U
L1
/V
5 ms
U
L2
RMS
RMS measurement of voltage U
L2
/V
5 ms
U
L3
RMS
RMS measurement of voltage U
L3
/V
5 ms
Pick-up
The
U
set
setting parameter controls the pick-up of the U> function. This defines the maximum allowed
measured voltage before action from the function. The function constantly calculates the ratio
between the
U
set
and the measured magnitude (
U
m
) for each of the three voltages. The reset ratio of
97 % is built into the function and is always relative to the
U
set
value. The setting value is common for
all measured amplitudes, and when the
U
m
exceeds the
U
set
value (in single, dual or all voltages) it
triggers the pick-up operation of the function.
A
AQ
Q-F213
-F213
Instruction manual
Version: 2.04
164