Transient Fault; Permanent Fault And Reclosing Unsuccessful Signal; Lock-Out Initiation - ABB REB670 Applications Manual

1MRK 505 337-UUS -
12.2.2.17
12.2.2.18
12.2.2.19
Application manual

Transient fault

After the Reclosing command the reset timer keeps running for the set time. If no tripping
occurs within this time, tReset, the Auto-Reclosing will reset. The CB remains closed and
the operating gear recharges. The input signals 52a and CBREADY will be set

Permanent fault and reclosing unsuccessful signal

If a new trip occurs, and number of reclosing shots is set to 1, a new input signal RI or
TRSOTF appears, after the CB closing command, the output UNSUCCL (unsuccessful
closing) is set high. The timer for the first shot can no longer be started. Depending on the
set number of Reclosing shots further shots may be made or the Reclosing sequence is
ended. After reset timer time-out the Auto-Reclosing function resets, but the CB remains
open. The "CB closed" information through the input 52a is missing. Thus, the reclosing
function is not ready for a new reclosing cycle.
Normally, the signal UNSUCCL appears when a new trip and start is received after the last
reclosing shot has been made and the auto-reclosing function is blocked. The signal resets
after reset time. The "unsuccessful" signal can also be made to depend on CB position
input. The parameter UnsucClByCBChk should then be set to CBCheck, and a timer
tUnsucCl should be set too. If the CB does not respond to the closing command and does
not close, but remains open, the output UNSUCCL is set high after time tUnsucCl. The
Unsuccessful output can for example, be used in Multi-Breaker arrangement to cancel the
auto-reclosing function for the second breaker, if the first breaker closed onto a persistent
fault. It can also be used to generate a Lock-out of manual closing until the operator has
reset the Lock-out, see separate section.

Lock-out initiation

In many cases there is a requirement that a Lock-out is generated when the auto-reclosing
attempt fails. This is done with logic connected to the in- and outputs of the Autoreclose
function and connected to Binary IO as required. Many alternative ways of performing the
logic exist depending on whether manual closing is interlocked in the IED, whether an
external physical Lock-out relay exists and whether the reset is hardwired, or carried out
by means of communication. There are also different alternatives regarding what shall
generate Lock-out. Examples of questions are:
• Shall back-up time delayed trip give Lock-out (normally yes)
• Shall Lock-out be generated when closing onto a fault (mostly)
• Shall Lock-out be generated when the Autorecloser was OFF at the fault or for
example, in Single phase AR mode and the fault was multi-phase (normally not as no
closing attempt has been given)
• Shall Lock-out be generated if the Breaker did not have sufficient operating power for
an auto-reclosing sequence (normally not as no closing attempt has been given)
Section 12
Control
311