1.
Check that the input logical signal BLOCK to the BRCPTOC function block is logical zero
and note on the local HMI that the output signal TRIP from the BRCPTOC function block is
equal to the logical 0.
2.
Set the measured current (fault current) in one phase to about 110% of the set operating
current
IP>.
Observe to not exceed the maximum permitted overloading of the current circuits in the
terminal.
3.
Switch on the fault current and measure the operating time of BRCPTOC.
TRIP is controlled by Gate 13 in the configuration.
Use the TRIP signal from the configured binary output to stop the timer.
4.
Compare the measured time with the set value
tOper.
5.
Activate the BLOCK binary input.
6.
Switch on the fault current (110% of the setting) and wait longer than the set value
tOper.
No TRIP signal should appear.
7.
Switch off the fault current.
8.
Set the measured current (fault current) in same phase to about 90% of the set operating
current
IP>. Switch off the current.
9.
Switch on the fault current and wait longer than the set value
tOper.
No TRIP signal should appear.
10. Switch off the fault current.
12.5.15.2
Completing the test
SEMOD175021-42 v4
Continue to test another function or end the test by changing the
TestMode setting to Off.
Restore connections and settings to their original values, if they were changed for testing
purposes.
12.5.16
Negative-sequence time overcurrent protection for machines
NS2PTOC
GUID-48A6DA1D-5CF5-4C1B-B1A4-3F2C73851FD4 v2
GUID-F7AA2194-4D1C-4475-8853-C7D064912614 v4
When inverse time overcurrent characteristic is selected, the operate time of
the stage will be the sum of the inverse time delay and the set definite time
delay. Thus, if only the inverse time delay is required, it is important to set the
definite time delay for that stage to zero.
12.5.16.1
Verifying settings by secondary injection
GUID-EB788169-532A-4A3E-BBEC-DCB28169DF86 v6
1.
Connect the test set for injection of three-phase currents to the appropriate current
terminals of the IED.
2.
Go to Main menu/Settings/Setting group n/Current protection/
NegSeqOverCurr2Step/NSOn/General and make sure that the function is enabled, that
is
Operation is set to On.
3.
Inject current into IEDs in such a way that negative sequence component is created and
then verify that negative sequence component of the injected currents is calculated
correctly by the function. See example below for 1 A rated current transformer.
4.
Inject pure negative sequence current, that is, phase currents with exactly same
magnitude, reversed sequence and exactly 120° phase displaced into the IED with an
initial value below negative sequence current start level. No output signals should be
activated.
Note: If it is difficult to obtain pure negative sequence current for the secondary injection
test, a current corresponding to the two phase short-circuit condition can be used. A two
Section 12
1MRK 502 067-UEN B
Testing functionality by secondary injection
176
Commissioning manual
