Sample Busbar And Data - GE b30 Instruction Manual

OVERVIEW

8.1.2 Sample busbar and data

The figure shows a double bus arrangement with North and South buses. This station has five circuits (C-1 through C-5)
and a tiebreaker (B-7). Circuit C-1 is connected to the North bus; circuits C-2, C-3 and C-4 can be routed to either bus via
switches S-1 through S-6; circuit C-5 can be connected to either bus via breakers B-5 and B-6.
The table shows the assumed short circuit contributions of the connected circuits and their DC time constants.
Table 8-1: Basic fault data of the connected circuit
Circuit
C-1
C-2
C-3
C-4
C-5
The basic CT data is presented in the following table. The magnetizing characteristics of the three different types of CTs
8
used in this example are shown in the following figure.
Table 8-2: Basic CT data
CT
CT-1
CT-2
CT-3
CT-4
CT-5, CT-6
CT-7, CT-8
8-2
Figure 8-1: Sample bus configuration
I (kA) T (ms)
FAULT DC
0.00 N/A
0.00 N/A
6.00 5
5.00 30
3.00 40
Ratio V (V)
sat
600:5 144
600:5 144
1200:5 288
1000:5 240
1000:5 240
1200:5 288
CHAPTER 8: APPLICATION OF SETTINGS
R (Ω) Leads (m)
CTsec
0.34 210
0.34 205
0.64 200
0.54 200
0.54 180
0.64 200
B30 BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL