GE C70 Instruction Manual page 351

5 SETTINGS
• The current is initially interrupted.
• The breaker status is open.
• An elevated high frequency current condition occurs and the current subsequently drops out again.
The algorithm is illustrated in the state machine diagram shown below.
Figure 5–107: ALGORITHM ILLUSTRATION – STATE MACHINE TO DETECT RESTRIKE
In this way, a distinction is made between a self-extinguishing restrike and permanent breaker failure condition. The latter
can be detected by the breaker failure function or a regular instantaneous overcurrent element. Also, a fast succession of
restrikes will be picked up by breaker failure or instantaneous overcurrent protection.
The following settings are available for each element.
• BREAKER RESTRIKE 1 FUNCTION: This setting enable and disables operation of the breaker restrike detection ele-
ment.
• BRK RSTR 1 BLOCK: This setting is used to block operation of the breaker restrike detection element.
• BREAKER RESTRIKE 1 SOURCE: This setting selects the source of the current for this element. This source must
have a valid CT bank assigned.
• BREAKER RESTRIKE 1 PICKUP: This setting specifies the pickup level of the overcurrent detector in per-unit values
of CT nominal current.
• BREAKER RESTRIKE 1 RESET DELAY: This setting specifies the reset delay for this element. When set to "0 ms",
then FlexLogic operand will be picked up for only 1/8th of the power cycle.
• BRK RSTR 1 BRK OPEN: This setting assigns a FlexLogic operand indicating the open position of the breaker. It must
be logic "1" when breaker is open.
• BRK RSTR 1 OPEN CMD: This setting assigns a FlexLogic operand indicating a breaker open command. It must be
logic "1" when breaker is opened, either manually or from protection logic.
• BRK RSTR 1 CLS CMD: This setting assigns a FlexLogic operand indicating a breaker close command. It must be
logic "1" when breaker is closed.
GE Multilin
Capacitor bank
offline
Current
interruption
(overcurrent)
High-frequency
elevated current
Current
interruption
(overcurrent)
Restrike detected:
OP state asserted
C70 Capacitor Bank Protection and Control System
5.7 CONTROL ELEMENTS
Breaker open
command or breaker
open state
Breaker
close
Capacitor bank
online
Breaker
close
Breaker close
834768A1.CDR
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