The default value for IMinForward =2.5% is used for this test.
2. Inject the following analogue quantities given in secondary amperes and volts and wait for three
seconds to obtain the trip output (the default delay for tTrip=2s):
IN
1)
Magnitude=40mA; Angle=180 degrees
UN Magnitude=75V; Angle=0 degrees
1) Inject set value for IMinForward +1.5% of CT secondary rated current, note that 1.5% is stated accuracy for the
function.(That shall be ((2.5%+1.5%)/100)*1A=0.025A+0.015A when IMinForward =2.5% and CT rated secondary
is 1A).
3. The following signals shall be given from the APPTEF function:
• STUN at the beginning of injection.
• WRNFW as a 50ms pulse after approximately 35ms from the injection start.
• STFW after approximately 150ms (default value for tStart=150ms)
• TRIP after approximately 2.15s (after tStart+tTrip)
4. Inject the following analogue quantities given in secondary amperes and volts and wait for three
seconds:
IN
1)
Magnitude=10mA; Angle=180 degrees
UN Magnitude=75V; Angle=0 degrees
1) Inject set value for IMinForward –1.5% of CT secondary rated current, ( 0.025A-0.015A when IMinForward =2.5%
and CT rated secondary is 1A)).
5. The following signal is given from the APPTEF function:
• Only STUN at the beginning of injection.
The function did not operate for this forward EF now because the injected current
is below the set level.
Test of IMinReverse setting pickup value
GUID-158772EA-D4DA-415D-A388-C2D9837414ED v1
1. Change the following settings from the default values:
• OperationMode = Start and Trip in order to obtain the trip signal
• IN>=3% (minimum value) in order not to interfere with this pickup test
• IMinReverse =2.5% in order to be similar to the IN value
2. Inject the following analogue quantities given in secondary amperes and volts and wait for three
seconds:
Section 11 1MRK 504 165-UUS Rev. J
Testing functionality by secondary injection
202 Transformer protection RET670
Commissioning manual
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