Schweitzer Engineering Laboratories SEL-421-4, Instruction Manual

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5.5
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Functions
Current and Voltage Source Selection
Current Source Uses
Refer to the global settings in Table 8.13 on page 8.5 . Line-current source setting
LINEI and alternate line-current source settings ALINEI and ALTI, if used, iden-
tify the currents used in the following elements/features described later in this
section and in other sections:
➤
Fault location
➤
Open-phase detection logic
➤
LOP (loss-of-potential) logic
➤
FIDS (fault-type identification selection) logic
➤
Directional elements
➤
CVT (capacitor voltage transformer) transient detection logic
Table 5.3 Available Current Source Selection Settings Combinations When ESS := Y, NUMBK := 2
a
a
NA = not applicable.
NUMBK
(number of
breakers) ESS
(source
selection) LINEI
(line-current
source) ALINEI
(alternate line-
current source) BK1I
(Breaker 1
current source) BK2I
(Breaker 2
current source) IPOL
(polarizing
current)
2 Y IW IX IW IX NA
2 Y IW IX IW COMB NA
2 Y IW IX IW NA NA
2 Y IW IX IX COMB NA
2 Y IW IX IX NA NA
2 Y IW IX NA IX NA
2 Y IW IX NA COMB NA
2 Y IW IX NA NA NA
2 Y IW NA IW IX NA
2 Y IW NA IW COMB NA
2 Y IW NA IW NA IAX, IBX, ICX,
or NA
2 Y IW NA IX COMB NA
2 Y IW NA IX NA NA
2 Y IW NA NA IX NA
2 Y IW NA NA COMB NA
2 Y IW NA NA NA IAX, IBX, ICX,
or NA
2 Y COMB IX IW IX NA
2 Y COMB IX IW NA NA
2 Y COMB IX IX NA NA
2 Y COMB IX NA IX NA
2 Y COMB IX NA NA NA
2 Y COMB NA IW IX NA
2 Y COMB NA IW NA NA
2 Y COMB NA IX NA NA
2 Y COMB NA NA IX NA
2 Y COMB NA NA NA NA