Sel SEL-421 - Main and Alternate Line Current Source Assignments; Combined Currents for Line Current Source Assignment; Breaker Current Source Assignments

R.1.3
Date Code 20111215 Reference Manual SEL-421 Relay
Protection Functions
Current and Voltage Source Selection
Figure 1.2 Main and Alternate Line Current Source Assignments
Figure 1.3 Combined Currents for Line Current Source Assignment
Figure 1.4 Breaker Current Source Assignments
All the available current and voltage source selection settings combinations
are covered in Tab le 1. 1, Table 1.2, and Table 1.3 . Notice that global setting
NUMBK (Number of Breakers in Scheme; see Table 10.3 on page R.10.5)
influences available settings combinations covered in Table 1.1, Tab le 1. 2, and
Tab le 1.3. In general, if NUMBK := 1, then no settings directly involving a
second circuit breaker are made (i.e., Breaker 2 current source setting BK2I is
automatically set to NA and hidden, as indicated with the shaded cells in the
BK2I columns in Table 1.1 and Table 1.2). Also, for source-selection setting
ESS := N, the settings are forced to certain values and hidden, as indicated
with the shaded cells in the ESS := N rows in Tabl e 1.1 .
IW
IX
SEL-421
Main
Breaker
Alternate
Breaker
LINEI := IW
ALINEI := IX
IW
IX
SEL-421
LINEI := COMB
IW
SEL-421
BK2I := IW
IX
SEL-421
BK2I := IX