Ct Failure Detector; Breaker Restrike Scheme Logic - GE T60 Instruction Manual

5 SETTINGS
SETTING
BREAKER RESTRIKE 1
FUNCTION
= Enabled
AND
SETTING
BKR RSTR 1 BLK
= Off
SETTING
BREAKER RESTRIKE 1
SOURCE
= IA
= IB
= IC
SETTING
BKR RSTR 1 BKR OPEN
= Off
OR
SETTING
BKR RSTR 1 OPEN CMD
= Off
SETTING
BKR RSTR 1 CLS CMD
= Off
e) CT FAILURE DETECTOR

PATH: SETTINGS CONTROL ELEMENTS
 CT FAILURE
 DETECTOR
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
The CT failure function is designed to detect problems with system current transformers used to supply current to the relay.
This logic detects the presence of a zero-sequence current at the supervised source of current without a simultaneous
zero-sequence current at another source, zero-sequence voltage, or some protection element condition.
GE Multilin
SETTING
BREAKER RESTRIKE 1 PICKUP
RUN
RUN
Restrike detection logic
ARMED
Current interruption
detection logic
I
< 0.05 pu
mag
t
for > ¼ cycle
AND
Figure 5–154: BREAKER RESTRIKE SCHEME LOGIC

MONITORING ELEMENTS
CT FAIL FUNCTION:
Disabled
CT FAIL BLOCK:
Off
CT FAIL 3I0 INPUT 1:
SRC 1
CT FAIL 3I0 INPUT 1
PKP: 0.2 pu
CT FAIL 3I0 INPUT 2:
SRC 2
CT FAIL 3I0 INPUT 2
PKP: 0.2 pu
CT FAIL 3V0 INPUT:
SRC 1
CT FAIL 3V0 INPUT
PKP: 0.20 pu
CT FAIL PICKUP
DELAY: 1.000 s
CT FAIL TARGET:
Self-reset
CT FAIL EVENTS:
Disabled
T60 Transformer Protection System
SETTING
BREAKER RESTRIKE 1
RESET DELAY
0
0
0
RESET


CT FAILURE DETECTOR

Range: Disabled, Enabled
Range: FlexLogic operand
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: 0.0 to 2.0 pu in steps of 0.1
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: 0.0 to 2.0 pu in steps of 0.1
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: 0.00 to 2.00 pu in steps of 0.01
Range: 0.000 to 65.535 s in steps of 0.001
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
5.7 CONTROL ELEMENTS
T
RST
FLEXLOGIC OPERANDS
T
BKR RESTRIKE 1 OP A
RST
BKR RESTRIKE 1 OP B
BKR RESTRIKE 1 OP C
T
RST
FLEXLOGIC OPERAND
BKR RESTRIKE 1 OP
OR
834012A1.CDR
5-303
5