Figure. 5.5.4. - 124. Example of signals assignment for autoreclosing sequences
Figure. 5.5.4. - 125. Autoreclosing shot settings, two requests and two shots are initialized.
In this example for earth faults its own operating time settings are used and for overcurrent time delay
its set from autorecloser. Both fault types can initialize both of the shots with different settings. If the
fault evolves from earth fault AR2 to multi-phase fault, auto-recloser will use AR1 settings for the
reclosing. In this example the dead time in between of the rst and second shot is different due to need
for give more time for the air to cool and de-ionize in the case of overcurrent or multi-phase fault. If high
set overcurrent stage activates in any situation the autoreclosing sequence is ended. In this case nal
trip shall be issued and the feeder closing will be locked by autorecloser. Closing of the breaker will
require manual reset of the autorecloser lock before attempting to close the breaker. Manual reset can
be applied from SCADA or locally from the HMI of the IED.
Following graphs present the principle signaling of the autorecloser in different cases possible for this
type of line. The graphs describe the available requests status, autorecloser internal signal statuses,
timer statuses, breaker controls from autorecloser and breaker status signals.
Autorecloser operates closely with Object control and all of the breaker status and monitor signals are
forwarded from the selected Object to the autorecloser. Also circuit breaker Open and Close signals
are controlled through the dedicated Object. In cases when the breaker cannot be closed due to it
being not ready or breaker closing is waiting for synchrocheck allowance the wait state is forwarded to
autorecloser so that it waits for Object to acknowledge either successful closing or failure timeout.
Similar situation can arise in circuit breaker open command e.g. if the open is blocked due to SF6 gas
leakage. In the failure acknowledgements situations autorecloser is always put to lock-out state with
requirement for reset when the cause of the lock-out is cleared. Reset is done by external input to the
function or by closing the breaker.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
220
