GE C70 Instruction Manual page 372

CONTROL ELEMENTS
5.8.10.3 Breaker restrike
SETTINGS  CONTROL ELEMENTS  MONITORING ELEMENTS  BREAKER RESTRIKE 1(3)
 BREAKER RESTRIKE 1

5
One breaker restrike element is provided for each CT/VT module in the C70.
According to IEEE standard C37.100 entitled IEEE Standard Definitions for Power Switchgear, restrike is defined as "a
resumption of current between the contacts of a switching device during an opening operation after an interval of zero
current of ¼ cycle at normal frequency or longer."
The breaker restrike algorithm responds to a successful interruption of the phase current following a declaration of
capacitor bank offline as per the breaker pole indication. If a high-frequency current with a magnitude greater than the
threshold is resumed at least ¼ of a cycle later than the phase current interruption, then a breaker restrike condition is
declared in the corresponding phase and the
counters and other logic to facilitate the decision making process as to the appropriate actions upon detecting a single
restrike or a series of consecutive restrikes.
A restrike event (FlexLogic operand) is declared if all of the following hold:
• The current is initially interrupted
5-248
BREAKER RESTRIKE 1

FUNCTION: Disabled
BKR RSTR 1 BLOCK:

Off
BREAKER RESTRIKE 1

SOURCE: SRC 1
BREAKER RESTRIKE 1

PICKUP: 0.500 pu
BREAKER RESTRIKE 1

RESET DELAY: 0.100 s
BKR RSTR 1 BKR OPEN:

Off
BKR RSTR 1 OPEN CMD:

Off
BKR RSTR 1 CLS CMD:

Off
BREAKER RESTRIKE 1

TARGET: Self-reset
BREAKER RESTRIKE 1

EVENTS: Disabled
Figure 5-131: Typical restrike waveform and detection flag
10
8
6
4
2
0.01
0
–2
–4
–6
–8
OPERATE
–10
BRK RESTRIKE 1 OP
Range: Disabled, Enabled
Range: FlexLogic operand
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
Range: 0.10 to 2.00 pu in steps of 0.01
Range: 0.000 to 65.535 s in steps of 0.001
Range: FlexLogic operand
Range: FlexLogic operand
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
0.03
0.02
operand asserts for a short period of time. The user can add
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
time (ms)
0.05
834764A1.CDR