344
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CONTROL ELEMENTS
CHAPTER 7: PROTECTION
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.
•
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 will be sent to lockout. The scheme will be also 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 will remain 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 manually closed 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.
