CHAPTER 6: SETPOINTS
S4 CONTROLS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–153
BLOCK 1(3)
For details see
Upon assertion of the block selected operand, lockout will not be executed. When the
selected lockout blocking input drops out, and upon new trip, the trip and close output
relays will be locked out.
NOTE
NOTE:
The lockout state is applied by the relay to TRIP and CLOSE output relays only, that are
connected to the trip and close breaker coils respectively. If an attempt is made to close
the breaker directly, bypassing the relay outputs, (i.e. from the breaker control switch while
the protective relay applies lockout on its TRIP and CLOSE outputs,) the breaker may not
close, as the trip signal would have priority over the close signal. In some old breakers, the
attempt to close the breaker may lead to an intermittent close followed by an immediate
trip, as the lockout state of the relay's output # 1 (TRIP) would be energized.
Figure 6-64: Lockout logic diagram
Set Dominant
SETPOINT
BLOCK 1:
Off = 0
BLOCK 2:
Off = 0
BLOCK 3:
Off = 0
OR
SETPOINT
LOCKOUT FUNCTION
Disabled = 0
Enabled
SETPOINT
ANY TRIP
AN
D
LOGIC OPERAND
LOCKOUT OP
LOGIC OPERAND
LOCKOUT RESET
SETPOINT
INPUT 1
SETPOINT
INPUT 10
.
.
.
OR
AN
D
BLOCK RESET LOCKT
SETPOINT
RESET FROM PB RESET
Disabled= 0
Enabled
PB “RESET”
LOGIC OPERAND
LOCKOUT DPO
SETPOINT
Off
RESET LOCKOUT
OR
NON-
VOLATILE
LATCH
S
R
SETPOINT
LOCKOUT SUPVSN
On
898852A1.cdr