CHAPTER 7: PROTECTION CONTROL ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 347
Autoreclose lockout
When a reclose sequence is started by an initiate signal, the autoreclose scheme moves
into the reclose-in-progress state and starts the incomplete sequence timer. The setting of
this timer determines the maximum time interval allowed for a single reclose shot. If a
close breaker 1 or 2 signal is not present before this time expires, the scheme enters the
lockout state.
There are four other conditions that can take the scheme to the lockout state, as follows:
• Receipt of the Block input while in the reclose-in-progress state
• The reclosing program logic: when a three-phase initiate is present and the
autoreclose mode is either “1 Pole” or “3 Pole-A” (three-pole autoreclose for single-pole
faults only)
• Initiation of the scheme when the count is at the maximum allowed
• 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 is sent to lockout. The scheme also is sent to lockout if one
breaker fails to reclose and the setting
Breaker Failure Option setting is “Lockout.”
Once the lockout state is set, it remains latched until one or more of the following occurs:
• The scheme is intentionally reset from lockout, employing the
Reset setting of the
autorecloser
• The breaker or breakers are closed manually from the panel switch, SCADA, or other
remote control through the
Breaker Manual Close setting
• Ten seconds after breaker control detects that the breaker or breakers were closed
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