GE B90 Instruction Manual page 368

OVERVIEW
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
used in this example are shown in the following figure.
Table 8-2: Basic CT data
CT
CT-1
8
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
B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL