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1MRK 504 165-UEN Rev. K
5.
Repeat steps
signal disappears.
6.
Record the measured current and calculate the corresponding zero-sequence current
according to the equation (observe that the currents in the equation are phasors):
3
IECEQUATION00019 V1 EN-US
Where:
I
IECEQUATION00020 V1 EN-US
7.
Compare the result with the set value of the zero-sequence operate current. Consider that the
set value 3I0< is in percentage of the base current IBase.
11.10.2.4
Measuring the operate value for the dead line detection function
1.
Apply three-phase voltages with their rated value and zero currents.
2.
Decrease the measured voltage in one phase until the DLD1PH signal appears.
3.
This is the point at which the dead line condition is detected. Check the value of the decreased
voltage with the set value UDLD< (UDLD< is in percentage of the base voltage UBase).
4.
Apply three-phase currents with their rated value and zero voltages.
5.
Decrease the measured current in one phase until the DLD1PH signal appears.
6.
This is the point at which the dead line condition is detected. Check the value of the decreased
current with the set value IDLD< (IDLD< is in percentage of the base current IBase).
11.10.2.5
Checking the operation of the du/dt and di/dt based function
Check the operation of the du/dt and di/dt based function if included in the IED.
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.
Change the voltages and currents in all three phases simultaneously.
The voltage change must be higher than the set value DU> and the current change must be
lower than the set value DI<.
•
•
3.
Apply normal conditions as in step 1.
The BLKU, BLKZ and 3PH signals should reset, if activated, see step
4.
Change the voltages and currents in all three phases simultaneously.
The voltage change must be higher than the set value DU> and the current change must be
higher than the set value DI<.
The BLKU, BLKZ and 3PH signals should not appear.
5.
Repeat step 2.
6.
Connect the nominal voltages in all three phases and feed a current below the operate level in
all three phases.
7.
Keep the current constant. Disconnect the voltage in all three phases simultaneously.
The BLKU, BLKZ and 3PH signals should not appear.
Transformer protection RET670
Commissioning manual
1
and 2. Then slowly increase the measured current in one phase until the BLKU
×
+
+
I
=
I
I
I
0
L1
L2
L3
,
I and I
L
1
L
2
L
3
The BLKU and BLKZ signals appear without any time delay. The BLKZ signal will be
activated only if the internal deadline detection is not activated at the same time.
3PH should appear after 5 seconds, if the remaining voltage levels are lower than the set
UDLD< of the dead line detection function.
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Testing functionality by secondary injection
are the measured phase currents
GUID-4ABF1FD4-F6D3-4109-AFE5-552875E558A0 v4
1
and 2.
Section 11
(Equation 120)
M1405-96 v12
225
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