CHAPTER 5: SETTINGS
CONTROL ELEMENTS
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
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5
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 also resets. 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 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.
Lockout
When a reclose sequence starts by an initiate signal, the 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 goes to “Lockout”.
There are four other conditions that can take the scheme to the Lockout state, as follows:
•
Receipt of ‘Block’ input while in the reclose-in-progress state
•
The reclosing program logic — When a 3P Initiate is present and the autoreclose mode is either 1 Pole or 3Pole-A (3
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 is also sent to Lockout if one breaker fails to reclose and the setting
AR BKR FAIL OPTION
is set
to “Lockout”.
Once the Lockout state is set, it is 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(s) is(are) manually closed from panel switch, SCADA, or other remote control through the
AR BRK MAN
CLOSE
setting;
•
10 seconds after breaker control detects that breaker(s) were closed
Breaker open before fault
A logic circuit is provided that inhibits the close breaker 1 and close breaker 2 outputs if a reclose initiate (RIP) indicator is
not present within 30 ms of the Breaker Any Phase Open input. This feature is intended to prevent reclosing if one of the
breakers was open in advance of a reclose initiate input to the recloser. This logic circuit resets when the breaker is closed.
Transfer reclose when breaker is blocked
•
When the reclosing sequence 1-2 is selected and Breaker 1 is blocked (
AR BKR1 BLK
operand is set) the reclose signal
can be transferred direct to the Breaker 2 if
AR TRANSFER 1 TO 2
is set to “Yes.” If set to “No”, the scheme is sent to
Lockout by the incomplete sequence timer.
•
When the reclosing sequence 2-1 is selected and Breaker 2 is blocked (
AR BKR2 BLK
operand is set) the reclose signal
can be transferred direct to the Breaker 1 if
AR TRANSFER 2 TO 1
is set to “Yes.” If set to “No” the scheme is sent to
Lockout by the incomplete sequence timer.
Force three-pole tripping
The reclosing scheme contains logic that is used to signal trip logic that three-pole tripping is required for certain
conditions. This signal is activated by any of the following:
•
Autoreclose scheme is paused after it was initiated
•
Autoreclose scheme is in the lockout state
•
Autoreclose mode is programmed for three-pole operation
•
The shot counter is not at 0; that is, the scheme is not in the reset state. This ensures a second trip is three-pole when
reclosing onto a permanent single phase fault.
•
1.25 cycles after the single-pole reclose is initiated by the
AR 1P INIT
signal
