GE L90 User Manual

5-392 L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CONTROL ELEMENTS CHAPTER 5: SETTINGS
5
5.8.12.8 Directional comparison blocking 1
SETTINGS  CONTROL ELEMENTS  PILOT SCHEMES  BLOCKING1 SCHEME
The Directional Comparison Blocking1 (DCB1) scheme operates the same way as the Directional Comparison Blocking
(DCB) scheme, except hard-coded connections to phase and ground distance elements are removed to allow the user to
choose FlexLogic operands to identify forward or reverse direction fault, such as ground OC directional elements for
example. This gives the user more flexibility and better coordination when employing this scheme.
Settings description and application guidance for DCB scheme apply to DCB1 scheme with the following exceptions.
BLK1 SCHME DIR FWD1-3 — Each setting defines the FlexLogic operand of a protection element for identifying forward faults
on the protected line, and thus, for initiating operation of the scheme. Good directional integrity is the key requirement for
an over-reaching forward-looking protection element.
 BLOCKING1 SCHEME


BLOCKING1 SCHEME
FUNCTION: Disabled
Range: Disabled, Enabled

BLOCK1 SCHEME BLOCK:
Off
Range: FlexLogic operand

BLOCK1 RX CO-ORD PKP
DELAY: 0.010 s
Range: 0.000 to 65.535 s in steps of 0.001

TRANS BLOCK1 PICKUP
DELAY: 0.030 s
Range: 0.000 to 65.535 s in steps of 0.001

TRANS BLOCK1 RESET
DELAY: 0.090 s
Range: 0.000 to 65.535 s in steps of 0.001

BLOCK1 SCHEME SEAL-
IN DELAY: 0.010 s
Range: 0.000 to 65.535 s in steps of 0.001

BLK1 SCHME DIR FWD1:
Off
Range: FlexLogic operand


BLK1 SCHME DIR FWD3:
Off
Range: FlexLogic operand

BLK1 SCHME DIR REV1:
Off
Range: FlexLogic operand


BLK1 SCHME DIR REV3:
Off
Range: FlexLogic operand

BLK1 FORCE TX STOP1:
Off
Range: FlexLogic operand

BLK1 FORCE TX STOP2:
Off
Range: FlexLogic operand

BLOCK1 SCHEME NO OF
COMM BITS: 1
Range: 1, 2, or 4

BLOCK1 SCHEME RX1:
Off
Range: FlexLogic operand


BLOCK1 SCHEME RX4:
Off
Range: FlexLogic operand

BLOCK1 SCHEME
TARGET: Self-Reset
Range: Self-Reset, Latched, Disabled

BLOCK1 SCHEME
EVENTS: Disabled
Range: Disabled, Enabled

GE L90 Specifications

General

Brand	GE
Model	L90
Category	Relays
Language	English