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 pickup 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.
11.12.3.3 Weak end infeed logic
M14947-37 v2
Weak-end infeed logic at permissive overreach schemes
M14947-39 v5
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
M14947-52 v7
Only one type of fault is sufficient, with the current reversal and weak-end infeed logic for distance
protection function ZCRWPSCH (85). Apply three faults (one in each phase). For phase A-G fault, set
these parameters:
Table 40: Phase A-G parameter values
Phase
I (Amps) Phase-angle
(Deg)
V (Volts) Phase-angle
(Deg)
A 0 0 Set less than UPN<
PU27PN
0
B 0 240 69.3 240
C 0 120 69.3 120
If wanted, change all settings cyclically for other faults (BG andCG).
The setting parameter WEI is set to Echo & Trip.
1. Apply input signals according Table 40.
2. Activate the receive (CR) signal.
3. After the IED has operated, turn off the input signals.
4. Check that trip, send signal, and indication are obtained.
The ECHO output gives only a 200 ms pulse.
Section 11 1MRK 504 165-UUS Rev. J
Testing functionality by secondary injection
268 Transformer protection RET670
Commissioning manual
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