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1MRK 511 409-UUS Rev. K
11.8.2.3
Measuring the trip value for the zero-sequence function
Measure the trip value for the zero-sequence 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.
Slowly decrease the measured voltage in one phase until the BLKV signal appears.
3.
Record the measured voltage and calculate the corresponding zero-sequence voltage according to
the equation (observe that the voltages in the equation are phasors):
×
3
EQUATION1819-ANSI V1 EN-US
Where:
V V
EQUATION1820-ANSI V1 EN-US
4.
Compare the result with the set value of the zero-sequence tripping voltage (consider that the set
value 3V0Pickup is in percentage of the base voltage.)
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
ANSIEQUATION00019 V1 EN-US
Where:
I
ANSIEQUATION00020 V1 EN-US
7.
Compare the result with the set value of the zero-sequence trip current. Consider that the set value
3I0< is in percentage of the base current IBase.
11.8.2.4
Measuring the trip 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 VDLDPU (VDLDPU is in percentage of the base voltage VBase).
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 IDLDPU (IDLDPU is in percentage of the base current IBase).
Phasor measurement unit RES670
Commissioning manual
=
+
+
V
V
V
V
0
A
B
C
V
and
are the measured phase voltages
A
B
C
1
and 2. Then slowly increase the measured current in one phase until the BLKV
+
+
I
=
I
I
I
0
A
B
C
,
I and I
A
B
C
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Testing functionality by secondary injection
are the measured phase currents
GUID-4ABF1FD4-F6D3-4109-AFE5-552875E558A0 v4
Section 11
M1405-72 v11
(Equation 97)
(Equation 98)
131
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