Current Reversal Logic; Weak End Infeed Logic - ABB rec670 Commissioning Manual

Section 10
Testing functionality by secondary injection
10.10.2.1
10.10.2.2
170
The current reversal logic and the weak-end infeed functions are tested during the
secondary-injection test of the impedance or overcurrent protection zones together
with the scheme communication logic for the distance protection function ZCPSCH.

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
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.
1. Activate the receive (CRL) signal.
2. Set the healthy condition to an impedance at 50% of the reach of the reverse zone
connected to IRV.
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.

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.
1MRK 511 360-UEN A
Bay control REC670 2.1 IEC
Commissioning manual