GE L90

CHAPTER 5: SETTINGS CONTROL ELEMENTS
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 5-401
5
The signal used to initiate the autoreclose scheme is the trip output from protection. This signal can be single pole tripping
for single phase faults and three phase tripping for multi-phase faults. The autoreclose scheme has five operating states.
Table 5-42: Autoreclose states
Autoreclose programs
The autorecloser provides four programs that can cause from one to four reclose attempts (shots). After the first shot, all
subsequent recloses are always three-pole. If the maximum number of shots selected is “1” (only one reclose attempt) and
the fault is persistent, after the first reclose the scheme goes to lockout upon another Initiate signal.
For the three-pole reclose programs (modes 3 and 4), an AR FORCE 3-P FlexLogic operand is set. This operand can be used in
connection with the tripping logic to cause a three-pole trip for single-phase faults.
Table 5-43: Autoreclose programs
The four autoreclose modes are described as follows:
• 1 & 3 Pole — In this mode, the autorecloser starts the
AR 1-P DEAD TIME timer for the first shot if the autoreclose is
single-phase initiated, the
AR 3-P DEAD TIME 1 timer if the autoreclose is three-pole initiated, and the AR 3-P DEAD TIME 2
timer if the autoreclose is three-phase time delay initiated. If two or more shots are enabled, the second, third, and
fourth shots are always three-pole and start the
AR 3-P DEAD TIME 2(4) timers.
• 1 Pole — In this mode, the autorecloser starts the
AR 1-P DEAD TIME for the first shot if the fault is single phase. If the
fault is three-phase or a three-pole trip on the breaker occurred during the single-pole initiation, the scheme goes to
lockout without reclosing. If two or more shots are enabled, the second, third, and fourth shots are always three-pole
and start the
AR 3-P DEAD TIME 2(4) timers.
• 3 Pole-A — In this mode, the autorecloser is initiated only for single phase faults, although the trip is three pole. The
autorecloser uses the
AR 3-P DEAD TIME 1 for the first shot if the fault is single phase. If the fault is multi phase the
scheme goes to Lockout without reclosing. If two or more shots are enabled, the second, third, and fourth shots are
always three-phase and start the
AR 3-P DEAD TIME 2(4) timers.
• 3 Pole-B — In this mode, the autorecloser is initiated for any type of fault and starts the
AR 3-P DEAD TIME 1 for the first
shot. If the initiating signal is AR 3P TD INIT the scheme starts AR 3-P DEAD TIME 2 for the first shot. If two or more shots
are enabled, the second, third, and fourth shots are always three-phase and start the
AR 3-P DEAD TIME 2(4) timers.
Basic reclosing operation
Reclosing operation is determined primarily by the AR MODE and AR BKR SEQUENCE settings. The reclosing sequences are
started by the initiate inputs. A reclose initiate signal sends the scheme into the reclose-in-progress (RIP) state, asserting
the AR RIP FlexLogic operand. The scheme is latched into the RIP state and resets only when an AR CLS BKR 1 (autoreclose
breaker 1) or AR CLS BKR 2 (autoreclose breaker 2) operand is generated or the scheme goes to the Lockout state.
State Characteristic
Enabled Scheme is permitted to operate
Disabled Scheme is not permitted to operate
Reset Scheme is permitted to operate and shot count is reset to 0
Reclose in progress Scheme has been initiated but the reclose cycle is not finished (successful or not)
Lockout Scheme is not permitted to operate until reset received
Mode Autoreclose
mode
First shot Second shot Third shot Fourth shot
Single-
phase fault
Multi-phase
fault
Single-
phase fault
Multi-phase
fault
Single-
phase fault
Multi-phase
fault
Single-
phase fault
Multi-phase
fault
1 1 & 3 Pole 1 Pole 3 Pole 3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
2 1 Pole 1 Pole Lockout 3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 3 Pole-A 3 Pole Lockout 3 Pole or
Lockout
Lockout 3 Pole or
Lockout
Lockout 3 Pole or
Lockout
Lockout
4 3 Pole-B 3 Pole 3 Pole 3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout
3 Pole or
Lockout