•
There should be no change in the high status of the output signals
BLKU and BLKZ.
•
The signal 3PH will appear.
8.
Establish normal voltage and current operating conditions simultaneously and
observe the corresponding output signals.
They should change to logical 0 as follows:
•
Signal 3PH after about 25ms
•
Signal BLKU after about 50ms
•
Signal BLKZ after about 200ms
6.6.2.2
Measuring the operate value for the negative sequence function
Measure the operate value for the negative sequence function.
1.
Simulate normal operating conditions with the three-phase currents in phase
with their corresponding phase voltages and with all of them equal to their
rated values.
2.
Slowly decrease the measured voltage in one phase until the BLKU signal
appears.
3.
Record the measured voltage and calculate the corresponding negative-
sequence voltage according to the equation.
Observe that the voltages in the equation are phasors.
3 U
2
×
U
L1
a
2
U
L2
a
+
×
U
L3
×
+
=
EQUATION707 V1 EN
(Equation 13)
Where:
U
L1
U
L2
and
U
L3
EQUATION708 V1 EN
= the measured phase voltages
a
1 e
j
2
p
×
3
-----------
×
0 5 j
3
2
-------
+
,
–
=
=
EQUATION709 V1 EN
4.
Compare the result with the set value (consider that the set value
3U2>
is in
percentage of the base voltage
UBase
) of the negative-sequence operating
voltage.
6.6.2.3
Measuring the operate value for the zero-sequence function
Measure the operate value for the zero-sequence function.
1MRK 511 248-UEN -
Section 6
Testing functionality
69
Commissioning Manual
