through the input 52a is missing. Thus, the reclosing function is not ready for a newreclosing cycle.Normally, the signal UNSUCCL appears when a new trip and start is received after the lastreclosing shot has been made and the auto-reclosing function is blocked. The signal resetsafter reset time. The “unsuccessful” signal can also be made to depend on CB positioninput. The parameter UnsucClByCBChk should then be set to CBCheck, and a timertUnsucCl should be set too. If the CB does not respond to the closing command and doesnot close, but remains open, the output UNSUCCL is set high after time tUnsucCl. TheUnsuccessful output can for example, be used in Multi-Breaker arrangement to cancel theauto-reclosing function for the second breaker, if the first breaker closed onto a persistentfault. It can also be used to generate a Lock-out of manual closing until the operator hasreset the Lock-out, see separate section.11.2.2.12 Lock-out initiationIn many cases there is a requirement that a Lock-out is generated when the auto-reclosingattempt fails. This is done with logic connected to the in- and outputs of the Autoreclosefunction and connected to Binary IO as required. Many alternative ways of performing thelogic exist depending on whether manual closing is interlocked in the IED, whether anexternal physical Lock-out relay exists and whether the reset is hardwired, or carried outby means of communication. There are also different alternatives regarding what shallgenerate 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 Auto-Recloser was OFF at the fault• Shall Lock-out be generated if the Breaker did not have sufficient operating power foran auto-reclosing sequence (normally not as no closing attempt has been given)In figures 137 and 138 the logic shows how a closing Lock-out logic can be designed withthe Lock-out relay as an external relay alternatively with the Lock-out created internallywith the manual closing going through the Synchro-check function. An example of Lock-out logic.1MRK 506 334-UUS A Section 11Control309Application manual
