5.7 CONTROL ELEMENTS
The scheme has a pre-wired input that indicates breaker status.
BKR 3 POLE OPEN: This setting selects a FlexLogic™ operand which indicates that the breaker has opened three
pole and the autoreclose scheme can start timing the three pole dead time. The scheme has a pre-wired input that indi-
cates breaker status.
AR 3-P DEAD TIME 1: This is the dead time following the first three pole trip. This intentional delay can be used for a
high-speed three-pole autoreclose. However, it should be set longer than the estimated de-ionizing time following the
AR 3-P DEAD TIME 2: This is the dead time following the second three-pole trip or initiated by the
This intentional delay is typically used for a time delayed three-pole autoreclose (as opposed to high speed three-pole
AR 3-P DEAD TIME 3: This setting represents the dead time following the third three-pole trip.
AR 3-P DEAD TIME 4: This setting represents the dead time following the third three-pole trip.
AR EXTEND DEAD T 1: This setting selects an operand that will adapt the duration of the dead time for the first shot
to the possibility of non-simultaneous tripping at the two line ends. Typically this is the operand set when the communi-
cation channel is out of service
AR DEAD TIME 1 EXTENSION: This timer is used to set the length of the dead time 1 extension for possible non-
simultaneous tripping of the two ends of the line.
AR RESET: This setting selects the operand that forces the autoreclose scheme from any state to reset. Typically this
is a manual reset from lockout, local or remote.
AR RESET TIME: A reset timer output resets the recloser following a successful reclosure sequence. The setting is
based on the breaker time which is the minimum time required between successive reclose sequences.
AR BKR CLOSED: This setting selects an operand that indicates that the breakers are closed at the end of the reset
time and the scheme can reset.
AR BLOCK: This setting selects the operand that blocks the autoreclose scheme (it can be a sum of conditions such
as: time delayed tripping, breaker failure, bus differential protection, etc.). If the block signal is present before autore-
close scheme initiation the
is in the RIP state the scheme will be sent to lockout.
AR PAUSE: The pause input offers the ability to freeze the autoreclose cycle until the pause signal disappears. This
may be done when a trip occurs and simultaneously or previously, some conditions are detected such as out-of step or
loss of guard frequency, or a remote transfer trip signal is received. When the pause signal disappears the autoreclose
cycle is resumed. This feature can also be used when a transformer is tapped from the protected line and a reclose is
not desirable until the it is disconnected from the line. In this situation, the reclose scheme is paused until the trans-
former is disconnected.
AR INCOMPLETE SEQ TIME: This timer is used to set the maximum time interval allowed for a single reclose shot. It
is started whenever a reclosure is initiated and is active until the
ditions allowing a breaker closure are not satisfied when this time expires, the scheme goes to "Lockout". The mini-
mum permissible setting is established by the
wait time for the breaker to open so that the reclose cycle can continue and/or for the
allow the reclose cycle to continue and/or for the
to be sent.
AR BLOCK BKR2: This input selects an operand that will block the reclose command for breaker 2. This condition can
be for example: breaker low air pressure, reclose in progress on another line (for the central breaker in a breaker and
a half arrangement), or a sum of conditions combined in FlexLogic™.
AR CLOSE TIME BKR2: This setting represents the closing time for the breaker 2 from the moment the 'Close' com-
mand is sent to the moment the contacts are closed.
AR TRANSFER 1 TO 2: This setting establishes how the scheme performs when the breaker closing sequence is 1-2
and breaker 1 is blocked. When set to "Yes" the closing command will be transferred direct to breaker 2 without waiting
the transfer time. When set to "No" the closing command will be blocked by the
will be sent to lockout by the incomplete sequence timer.
AR TRANSFER 2 TO 1: This setting establishes how the scheme performs when the breaker closing sequence is 2-1
and breaker 2 is blocked. When set to "Yes" the closing command will be transferred direct to breaker 1 without waiting
FlexLogic™ operand will be set. If the block signal occurs when the scheme
AR 3-P DEAD TIME 2
AR BKR1 BLK
L90 Line Current Differential System
timer setting. Settings beyond this will determine the
signal to disappear and allow the
AR BKR1 BLK
AR 3P TD INIT
signal is sent. If all con-
signal to reset and
AR CLOSE BKR1
signal and the scheme