GE D90 Plus Instruction Manual page 305

CHAPTER 7: PROTECTION
Breaker block
Reset after reclosure
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
A reclose command to a breaker is inhibited if it receives a user-defined block input or if it
is out-of-service. A logic circuit is also provided that inhibits a breaker reclose if that
breaker was open in advance of a reclose initiate input to the recloser. This logic circuit
resets when the breaker is closed.
Figure 237: Autoreclose scheme breaker block logic
For single breaker reclosing on a transient fault, the reset timer is started when a reclose
output signal is sent to close the breaker. If the reclosure sequence is successful (there is no
initiating signal and the breaker is closed) the reset timer will time out, returning the
scheme to the reset state with the shot counter set to 0 and ready for a new reclose cycle.
In two breaker schemes, if one breaker is in the out-of-service state and the other is closed
at the end of the reset time, the scheme will also reset. If at the end of the reset time at
least one breaker, which is not in the out-of-service state, is open the scheme will be sent
to lockout. The reset timer is stopped if the reclosure sequence is not successful: an
initiating signal present or the scheme is in lockout state. The reset timer is also stopped if
the breaker is manually closed or the scheme is otherwise reset from lockout.
Figure 238: Autoreclose scheme reset logic
CONTROL ELEMENTS
297