GE D60 - Page 469

GE Multilin D60 Line Distance Protection System 5-335
5 SETTINGS 5.7 CONTROL ELEMENTS
5
g) DIRECTIONAL COMPARISON BLOCKING
PATH: SETTINGS  CONTROL ELEMENTS  PILOT SCHEMES  BLOCKING SCHEME
Generally, the scheme compares the direction to a fault at all terminals of the line. Unlike the permissive schemes, the
absence of a blocking signal permits operation of the scheme. Consequently, the scheme is biased toward dependability
and requires an "on/off" type of signaling.
By default this scheme uses only a forward-looking over-reaching zone 2 distance element to identify forward faults.
Ground directional overcurrent functions available in the relay can be used in conjunction with the zone 2 distance element
to increase the coverage for high-resistance faults. Also by default, only a reverse-looking zone 4 distance element to iden-
tify reverse faults. Ground directional overcurrent functions available in the relay can be used in conjunction with the zone 4
distance element for better time and sensitivity coordination.
For proper operation, the zone 2 and 4 phase and ground distance elements must be enabled, configured and set per rules
of distance relaying. If used by this scheme, the selected ground directional overcurrent functions must be enabled, config-
ured, and programmed accordingly.
In single-pole tripping applications, the scheme uses local fault type identification provided by the phase selector together
with information received from the remote terminal.
 BLOCKING SCHEME

BLOCKING SCHEME
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
BLOCK SCHEME BLOCK:
Off
Range: FlexLogic operand
MESSAGE
BLOCK RX CO-ORD PKP
DELAY: 0.010 s
Range: 0.000 to 65.535 s in steps of 0.001
MESSAGE
TRANS BLOCK PICKUP
DELAY: 0.030 s
Range: 0.000 to 65.535 s in steps of 0.001
MESSAGE
TRANS BLOCK RESET
DELAY: 0.090 s
Range: 0.000 to 65.535 s in steps of 0.001
MESSAGE
BLOCK SCHEME SEAL-IN
DELAY: 0.010 s
Range: 0.000 to 65.535 s in steps of 0.001
MESSAGE
GND DIR O/C FWD:
Off
Range: FlexLogic operand
MESSAGE
GND DIR O/C REV:
Off
Range: FlexLogic operand
MESSAGE
BLOCK SCHEME NO OF
COMM BITS: 1
Range: 1, 2, or 4
MESSAGE
BLOCK SCHEME RX1:
Off
Range: FlexLogic operand
MESSAGE
BLOCK SCHEME RX2:
Off
Range: FlexLogic operand
MESSAGE
BLOCK SCHEME RX3:
Off
Range: FlexLogic operand
MESSAGE
BLOCK SCHEME RX4:
Off
Range: FlexLogic operand
MESSAGE
BLOCK SCHEME TARGET:
Self-Reset
Range: Self-Reset, Latched, Disabled
MESSAGE
BLOCK SCHEME EVENT:
Disabled
Range: Disabled, Enabled