Bus - GE B90 UR Series Instruction Manual

5.3 SYSTEM SETUP
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PATH: SETTINGS SYSTEM SETUP
 BUS ZONE 1 INPUT A

The number of available zones and their size (maximum number of inputs) are optional and controlled by the
software option portion of the order code. Please refer to the Ordering section in chapter 2 for detailed infor-
mation on the maximum number of zones and inputs for a given B90 model.
Four bus differential zones are available. Each zone is associated with its own bus differential protection and CT trouble
monitoring elements. A differential zone is defined by up to 24 pairs (inputs A to X) of current input–bus connection status
values.
• BUS 1A CT: This setting defines a current input to the zone. Selections include all the CT channels available in the
relay as per configured hardware. The protected bus zone is uniquely identified as the portion of the bus between the
selected current sources (CTs).
• BUS 1A DIRECTION: This setting configures the CT orientation with respect to the protected zone. Bus differential
and CT trouble decisions are based on current summation and thus correct orientation selection is important. The fig-
5
ure below shows a tie-breaker dividing a single bus into two sections, defined as zone 1 and zone 2. The tie-breaker
CT (F5) is common to both zones and therefore the respective direction settings are opposite. The CT polarity dots are
in relation to the protected zone and are terminated to the "common" of the tapped (1 A / 5 A) inputs. The polarity dots
for the zone 2 CTs face outward with respect to the bus; as such, the F5 to F8 direction settings are "IN". Similarly, the
F1 to F4 CTs for zone 1 are selected as "IN". However, the polarity dot orientation for the F5 CT faces inward with
respect to zone 1 and therefore the
• BUS 1A STATUS: This setting dynamically defines a connection status of a given feeder with respect to the differential
zone (dynamic bus replica). If a given feeder is connected to the zone and its current included into differential calcula-
tions, the FlexLogic™ operand used for this setting is "On"; if the current is excluded, the FlexLogic™ operand is "Off".
Typically, this setting is an appropriately filtered position of an isolator, a breaker or a tie-breaker.
In the case of an isolator connecting a feeder to a given section of a bus, the isolator monitoring feature produces a
reliable isolator position operand (
fourth B90 IED and the
before it may be configured as a
5-78
 

BUS

BUS ZONE 1(4)
BUS 1A CT:
F1
BUS 1A DIRECTION:
MESSAGE
IN
BUS 1A STATUS:
MESSAGE
Off
BUS 1E DIRECTION
ISOLATOR 1 POSITION
status operand must be sent over direct input/output communications
ISOLATOR 1 POSITION
BUS ZONE 1A(X) STATUS
ZONE 1
F1 F2 F3
ZONE 1:
BUS 1A CT = F1
BUS 1A DIRECTION = IN
BUS 1B CT = F2
BUS 1B DIRECTION = IN
BUS 1C CT = F3
BUS 1C DIRECTION = IN
BUS 1D CT = F4
BUS 1D DIRECTION = IN
BUS 1E CT = F5
BUS 1E DIRECTION = OUT
Figure 5–31: BUS ZONE DIRECTION SETTING
B90 Low Impedance Bus Differential System

BUS ZONE 1(4) INPUT A(X)
Range: available CT channels
Range: IN, OUT
Range: FlexLogic™ operand
setting is "OUT".
). Typically, the isolator monitoring feature is enabled in the
setting.
F5
ZONE 2
F4 F6 F7
ZONE 2:
BUS 2A CT = F5
BUS 2A DIRECTION = IN
BUS 2B CT = F6
BUS 2B DIRECTION = IN
BUS 2C CT = F7
BUS 2C DIRECTION = IN
BUS 2D CT = F8
BUS 2D DIRECTION = IN
836757A2.CDR
5 SETTINGS
5.3.4 BUS
F8
GE Multilin