GE c60 Instruction Manual page 322

GROUPED ELEMENTS
Output
The outputs from the schemes are:
• FlexLogic operands that report on the operation of portions of the scheme
• FlexLogic operand used to re-trip the protected breaker
• FlexLogic operands that initiate tripping required to clear the faulted zone. The trip output can be sealed-in for an
adjustable period.
• Target message indicating a failed breaker has been declared
• Illumination of the faceplate Trip LED (and the Phase A, B, or C LED, if applicable)
Main path sequence
0
AMP
0
PROTECTION OPERATION
(ASSUMED 1.5 cycles)
INITIATE (1/8 cycle)
FAULT
OCCURS
0 1
5
The current supervision elements reset in less than 0.7 of a power cycle for any multiple of pickup current as shown in the
following figure.
Settings
— This setting is used to select the breaker failure operating mode: single or three pole.
BF1 MODE
BF1 USE AMP SUPV
pickup level.
5-196
Figure 5-95: Breaker failure main path sequence
ACTUAL CURRENT MAGNITUDE
CALCULATED CURRENT MAGNITUDE
Rampdown
BREAKER INTERRUPTING TIME
(ASSUMED 3 cycles)
BREAKER FAILURE TIMER No. 2 (±1/8 cycle)
BREAKER FAILURE CURRENT DETECTOR PICKUP (1/8 cycle)
BREAKER FAILURE OUTPUT RELAY PICKUP (1/4 cycle)
2 3 4
Figure 5-96: Breaker failure overcurrent supervision reset time
0.8
0.6
0.4
0.2
0
0 20 40
Mul ple of pickup
— If set to "Yes," the element is initiated if current flowing through the breaker is above the supervision
FAILED INTERRUPTION
CORRECT INTERRUPTION
MARGIN
(Assumed 2 Cycles)
5 6 7
60 80 100 120
fault current
threshold setting
C60 BREAKER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
BACKUP BREAKER OPERATING TIME
(Assumed 3 Cycles)
8 9 10
Margin
Maximum
Average
140
836769A4.CDR
cycles
11
827083A6.CDR