The forward zone timer must be set longer than the tDelayRev set value.
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.
11.11.3.2 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 (85). Apply three faults (one in each phase).
For phase A-G fault, set these parameters:
Table 35: 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).
Section 11 1MRK 504 165-UUS -
Testing functionality by secondary injection
264 Transformer protection RET670 2.2 ANSI
Commissioning manual
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