shot can no longer be started. Depending on the set number of auto reclosing shotsfurther shots may be made or the auto reclosing sequence is ended. After reclaimtimer time-out the auto recloser resets, but the circuit breaker remains open. Thecircuit breaker closed information through the CBCLOSED input is missing. Thus,the auto recloser is not ready for a new auto reclosing cycle. Normally, theUNSUCCL output appears when a new start is received after the last auto reclosingshot has been made and the auto recloser is inhibited. The output signal resets afterreclaim time. The “unsuccessful” signal can also be made to depend on the circuitbreaker position input. The UnsucClByCBChk setting should then be set toCBCheck, and the tUnsucCl timer should be set too. If the circuit breaker does notrespond to the breaker closing command and does not close, but remains open, theUNSUCCL output is set high after the set tUnsucCl time. The UNSUCCL outputcan for example, be used in multi-breaker arrangement to cancel the auto reclosingfor the second circuit breaker, if the first circuit breaker closed onto a persistentfault. It can also be used to generate a lock-out of manual circuit breaker closinguntil the operator has reset the lock-out, see separate section.14.2.2.19 Lock-out initiation M12391-214 v8In many cases there is a requirement that a lock-out is generated when the autoreclosing attempt fails. This is done with logic connected to the in- and outputs ofthe auto recloser and connected to binary I/O as required. Many alternative ways ofperforming the logic exist depending on whether manual circuit breaker closing isinterlocked in the IED, whether an external physical lock-out relay exists andwhether the reset is hardwired, or carried out by means of communication. Thereare also different alternatives regarding what shall generate lock-out. Examples ofquestions 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 is Off at the fault or forexample, in single-phase auto recloser mode and the fault was multi-phase(normally not as no closing attempt has been given)• shall lock-out be generated if the circuit breaker did not have sufficientoperating power for an auto reclosing sequence (normally not as no autoclosing attempt has been given)In Figures 115 and 116 the logic shows how a closing lock-out logic can bedesigned with the lock-out relay as an external relay alternatively with the lock-outcreated internally with the manual closing going through the synchrocheckfunction. An example of lock-out logic.1MRK 511 401-UEN A Section 14ControlBay control REC670 2.2 IEC 311Application manual
