A permanent fault will cause the line protection to trip again when it recloses in anattempt to energize the line.The auto reclosing function allows a number of parameters to be adjusted.Examples:• number of auto reclosing shots• auto reclosing program• auto reclosing dead times for each shot12.2.2.1 Auto reclosing operation Off and On M12391-91 v6Operation of the automatic recloser can be set to Off and On by a setting parameter orby external control. The setting parameter Operation = Disabled, or Enabled sets thefunction to Off or On. With the settings Operation = Enabled and ExternalCtrl =Enabled , the control is made by input signal pulses to the inputs On and Off, forexample, from a control system or by a control switch.When the auto recloser is set On, the SETON output is set, and the auto recloserbecomes operative if other conditions such as circuit breaker is closed and circuitbreaker is ready are also fulfilled, the READY output is activated (high). Then the autorecloser is ready to accept a start.12.2.2.2 Initiate auto reclosing and conditions for start of a reclosing cycle M12391-94 v5The usual way to start an auto reclosing cycle, or sequence, is to start it at selectivetripping by line protection by applying a signal to the RI input. Starting signals can beeither, general trip signals or, only the conditions for differential, distance protectionzone 1 and distance protection aided trip. In some cases also directional ground faultprotection aided trip can be connected to start an auto reclose attempt. If general trip isused to start the auto recloser it is important to block it from other functions that shouldnot start an auto reclosing sequence.In cases where one wants to differentiate three-phase auto reclosing dead time, fordifferent power system configuration or at tripping by different protection stages, onecan also use the RI_HS input (initiate high-speed reclosing). When initiating RI_HS,the auto reclosing dead time for three-phase shot 1, t1 3PhHS is used and the closing isdone without checking the synchrocheck condition.A number of conditions need to be fulfilled for the start to be accepted and a new autoreclosing cycle to be started. They are linked to dedicated inputs. The inputs are:Section 12 1MRK 505 370-UUS AControl318 Busbar protection REB670 2.2 ANSIApplication manual
