354
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CONTROL ELEMENTS
CHAPTER 7: PROTECTION
Extend Dead Time 1
Range: any FlexLogic™ operand or shared operand
Default: Off
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 communication channel is out-of-service.
Dead Time 1 Extension
Range: 0.00 to 655.35 seconds in steps of 0.01
Default: 0.50 seconds
This setting specifies the length of the dead time 1 extension for possible non-
simultaneous tripping of the two ends of the line.
Reset
Range: any FlexLogic™ operand or shared operand
Default: Off
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.
Reset Time
Range: 0.00 to 655.35 seconds in steps of 0.01
Default: 60.00 seconds
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.
Breaker Closed
Range: any FlexLogic™ operand or shared operand
Default: Off
This setting selects an operand that indicates that the breaker(s) are closed at the end of
the reset time and the scheme can reset.
Block
Range: any FlexLogic™ operand or shared operand
Default: Off
This setting selects the operand that blocks the autoreclose scheme (it can be a sum of
conditions such as time delayed tripping, breaker failure, and differential protection). If
the block signal is present before autoreclose scheme initiation the
AR DISABLED
FlexLogic™ operand will be set. If the block signal occurs when the scheme is in the
reclose-in-progress state the scheme will be sent to lockout.
Pause
Range: any FlexLogic™ operand or shared operand
Default: Off
This setting 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. The autoreclose cycle is resumed when the pause
signal disappears. 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 transformer is disconnected.