Sel SEL-421 - Available Voltage Source-Selection Setting Combinations

R.1.7
Date Code 20111215 Reference Manual SEL-421 Relay
Protection Functions
Current and Voltage Source Selection
NA = not applicable
Shaded cells indicate settings forced to given values and hidden
SELOGIC setting ALTV controls the switching between voltages VY and VZ
for line voltage (assert setting ALTV to switch to designated alternate line
voltage ALINEV := VZ). Setting ALTV is automatically hidden and set to NA
if ALINEV := NA (no voltage switching can occur). Reasons for switching
from one three-phase voltage to another may be for loss-of-potential or bus
switching/rearrangement.
Default line voltage source VY and alternate line voltage source settings
(ALINEV and ALTV) identify the voltages 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
➤ Series-compensation line logic
➤ Load-encroachment logic
➤ OOS (out-of-step) logic
➤ Distance elements
➤ SOTF (switch-onto-fault) logic
➤ POTT (permissive overreaching transfer tripping) scheme logic
➤ Metering on page A.2.26, including synchrophasors
Table 1.4 Available Voltage Source-Selection Setting Combinations
NUMBK
(number of
breakers)
ESS
(source
selection)
Line Voltage
Source
ALINEV
(alternate line
voltage
source)
1 Y VY VZ or NA
1N VY
NA
1 1 VY VZ or NA
1 2 VY VZ or NA
1 3 not allowed
1 4 not allowed
2 Y VY VZ or NA
2N VY
NA
2 1 not allowed
2 2 not allowed
2 3 VY VZ or NA
2 4 VY VZ or NA