Transient Fault - ABB REL650 Applications Manual

Section 11
Control
11.3.2.15
11.3.2.16
11.3.2.17
326

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 a new input signal PICKUP 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 reclaim reset time. The "unsuccessful" signal can also be made to depend on CB
position input. The parameter UnsucClByCBChk should then be set to CB Check, 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
Auto-Reclose 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 generated when the Auto-Recloser was OFF at the fault
• 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)
1MRK 506 334-UUS A
Application manual