6–152
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S4 CONTROLS
CHAPTER 6: SETPOINTS
Lockout (86)
The purpose of the Lockout function is to prevent unwanted closing of the breaker after
being tripped by the operation of a protection element. When triggered, the lockout
maintains a constant trip signal to trip output relay #1. At the same time, the same signal is
used as a block into the close output relay logic to prevent any unwanted, non-safe close
commands to that relay.
The lockout block is removed upon a Lockout Reset signal sent to the relay. The Lockout
Reset can be initiated either by pressing the relay pushbutton RESET (after it is enabled to
perform Lockout resets), or by any contact, virtual, or remote input selected under the
Lockout Reset setpoint.
NOTE
NOTE:
Special care needs to be taken selecting the Lockout trigger in cases with Autoreclosure
(AR) enabled. In such cases, the lockout may be applied after the AR cycle is complete, and
the breaker is tripped. In cases of intermittent fault ending with successful AR, the Lockout
should not be applied.
FUNCTION
Range: Disabled, Enabled
Default: Disabled
For details see
INPUT 1(10)
Range: Off, Any Logic Operand
Default: Off
This setting selects an operand from the list of logic operands. The assertion of the
selected operand triggers lockout. Ten trigger input setpoints are provided.
LOCKOUT SUPERVISION
Range: Off, Any logic operand
Default: Off
This setting provides selection of any logic operand to supervise the initiation of lockout
state. As an example the open status of the breaker/breakers could be used for lockout
supervision.
LOCKOUT RESET
Range: Off, Any Logic Operand
Default: Off
This setting provides selection of any logic operand from the list of operands for
resetting the breaker lockout condition.
RESET FROM PB RESET
Range: Disabled, Enabled
Default: Disabled
If Enabled, pressing the front panel Reset pushbutton resets the Lockout. Otherwise,
when Disabled, pressing the Reset PB sends a common reset which does not reset the
Lockout.
BLOCK RESET LOCKOUT
Range: Off, Any Logic Operand
Default: Any Trip
This setting provides selection of any logic operand to block the reset action of the
lockout state. Usually if there is a presence of a trip condition, the reset command will
not be executed. The default value is selected as "Any Trip" operand.