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Section 11
Testing functionality by secondary injection
11.11.3.2
Current reversal logic
It is possible to check the delay of the CS send signal with tDelayRev by changing from a reverse to
a forward fault.
By continuously activating the CR input and changing from a reverse to a forward fault, the delay
tDelayRev can be checked.
Checking of current reversal
1.
Set the healthy condition to an impedance at 50% of the reach of the reverse zone connected
to IRV.
2.
Activate the receive (CRL) signal.
3.
After the start condition is obtained for reverse zone, apply a fault at 50% of the reach of the
forward zone connected to WEIBLK2.
4.
Check that correct trip outputs and external signals are obtained for the type of fault generated.
The operation time should be about the tDelayRev setting longer than the carrier accelerated
trip (TRIP) recorded for the permissive overreach scheme communication.
5.
Restore the forward and reverse zone timer to its original setting.
11.11.3.3
Weak end infeed logic
Weak-end infeed logic at permissive overreach schemes
1.
Check the blocking of the echo with the injection of a CRL signal >40ms after a reverse fault is
applied.
2.
Measure the duration of the echoed CS signal by applying a CRL receive signal.
3.
Check the trip functions and the voltage level for trip by reducing a phase voltage and applying
a CRL receive signal.
Testing conditions
Only one type of fault is sufficient, with the current reversal and weak-end infeed logic for distance
protection function ZCRWPSCH. Apply three faults (one in each phase). For phase L1-N fault, set
these parameters:
Table 41:
Phase
L1
L2
L3
If wanted, change all settings cyclically for other faults (L2-N and L3-N).
222
The reverse zone timer must not operate before the forward zone fault is applied.
The user might need to block the reverse zone timer setting during testing of current
reversal.
The forward zone timer must be set longer than the tDelayRev set value.
Phase L1-N parameter values
I (Amps)
Phase-angle
(Deg)
0
0
0
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V (Volts)
0
Set less than UPN<
240
63
120
63
1MRK 505 378-UEN Rev. K
Phase-angle
(Deg)
0
240
120
Line differential protection RED670
Commissioning manual
M14947-8 v3
M14947-13 v9
M14947-37 v2
M14947-39 v5
M14947-52 v7
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