Schweitzer Engineering Laboratories SEL-421-4 - Table 5.54 Quadrilateral Phase-Distance Elements Relay Word Bits

5.89
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Functions
Quadrilateral Phase-Distance Elements
When you set the number of zones you want to enable (E21XP), this setting
applies to both the high-speed and conventional elements. For example, E21XP =
2 makes two zones (Zone 1 and Zone 2) available for both the high-speed and
conventional elements and hides the remaining zones.
Table 5.54 shows the Relay Word bits for quadrilateral phase-distance elements.
Figure 5.70 shows the logic of the Zone 1 conventional quadrilateral phase-
distance element for the AB loop. Fault calculations for BC and CA faults have
similar logics.
Table 5.54 Quadrilateral Phase-Distance Elements Relay Word Bits
Relay Word Bit Description
XAB1 Zone 1 quad A-B phase element
XBC1 Zone 1 quad B-C phase element
XCA1 Zone 1 quad C-A phase element
XAB2 Zone 2 quad A-B phase element
XBC2 Zone 2 quad B-C phase element
XCA2 Zone 2 quad C-A phase element
XAB3 Zone 3 quad A-B phase element
XBC3 Zone 3 quad B-C phase element
XCA3 Zone 3 quad C-A phase element
XAB4 Zone 4 quad A-B phase element
XBC4 Zone 4 quad B-C phase element
XCA4 Zone 4 quad C-A phase element
XAB5 Zone 5 quad A-B phase element
XBC5 Zone 5 quad B-C phase element
XCA5 Zone 5 quad C-A phase element