Auto-reclosing sequence from trip with two shot failure
For this earth fault autoreclosing scheme directional earth fault protection Trip signal to operate was set
as REQ2 starter which has Shot1 and Shot2 enabled with following settings. One rapid shot followed
by time delayed shot is set for this scheme.
Figure. 5.5.4. - 126. Settings for earth fault reclosing with two shots.
When Trip signal is used for the autorecloser cycle init then no additional starting or discrimination
times are used since the protection stage takes care of the breaker opening timings directly by its own
operation. Autorecloser therefore only monitors the status of the directional earth fault stage tripping
before initiating request and shots.
Figure. 5.5.4. - 127. Signal status graph of the permanent earth fault autoreclosing cycle.
1. Earth fault is found in the protected line which causes directional earth fault protection I0Dir> to
start and calculate the operating time for the trip.
2. I0Dir> trips and gives open command to the breaker open coil. Autoreclosing REQ2 is initiated
and AR running, AR2 Requested and Shot1 Running signals are activated.
3. Circuit breaker is opened and I0Dir> Trip signal is released and simultaneously REQ2 signal for
autorecloser is released. Recloser starts to calculate the Shot1 Dead Time for closing the
breaker.
4. Dead Time for Shot1 is exceeded and autorecloser sends close request for the Object breaker,
the close conditions are met and the breaker close command is sent to breaker close coil.
AQ-F255
Instruction manual
Version: 2.00
221
© Arcteq Relays Ltd