GE Multilin
B90 Low Impedance Bus Differential System
6-9
6 ACTUAL VALUES
6.3 METERING
6
Figure 6–1: UR PHASE ANGLE MEASUREMENT CONVENTION
6.3.3 BUS ZONE
PATH: ACTUAL VALUES
METERING
BUS
BUS ZONE 1(4)
These values display the differential and restraint currents phasors for each bus zone. The magnitudes are displayed in pri-
mary amperes (see chapter 8:
Theory of operation
for additional details).
There is no cutoff level applied to the differential and restraint currents computed by the B90. Therefore, a small dif-
ferential current reflecting CT inaccuracies and bus leakage current could be present during balanced conditions.
This is done to achieve a more accurate differential balance and provide the user a direct indication of the real dif-
ferential current, as excluding small currents or not accounting for CT errors may impose significant unaccounted
differential current. It is advisable to set the minimum pickup for 87B protection greater than the maximum differen-
tial current during normal load conditions.
6.3.4 CURRENTS
PATH: ACTUAL VALUES
METERING
CURRENTS
The metered current values for each terminal are displayed in this menu.
BUS ZONE 1
BUS ZONE 1 DIFF:
0.000 A 0.0°
MESSAGE
BUS ZONE 1 REST:
0.000 A 0.0°
CURRENTS
F1 CURRENT:
0.000 A
0.0°
MESSAGE
F2 CURRENT:
0.000 A
0.0°
MESSAGE
S8 CURRENT:
0.000 A
0.0°
827845A1.CDR
UR phase angle
reference
0
o
-45
o
-90
o
-135
o
-270
o
-225
o
-180
o
-315
o
positive
angle
direction
NOTE
Summary of Contents for B90
Page 10: ...x B90 Low Impedance Bus Differential System GE Multilin TABLE OF CONTENTS ...
Page 284: ...5 166 B90 Low Impedance Bus Differential System GE Multilin 5 8 TESTING 5 SETTINGS 5 ...
Page 334: ...10 8 B90 Low Impedance Bus Differential System GE Multilin 10 2 BATTERIES 10 MAINTENANCE 10 ...
Page 338: ...A 4 B90 Low Impedance Bus Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 460: ...C 30 B90 Low Impedance Bus Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 476: ...E 10 B90 Low Impedance Bus Differential System GE Multilin E 1 IEC 60870 5 104 APPENDIX E E ...
Page 502: ...viii B90 Low Impedance Bus Differential System GE Multilin INDEX ...
