Schweitzer Engineering Laboratories SEL-351A, Manual

Page: 329 / 666

9.19
Date Code 20080213
Instruction Manual SEL-351A Relay
Setting the Relay
Relay Word Bits (Used in SEL
OGIC
Control Equations)
5 50A 50A1 + 50A2 + 50A3 + 50A4 (see Figure 3.4 )
50B 50B1 + 50B2 + 50B3 + 50B4 (see Figure 3.4 )
50C 50C1 + 50C2 + 50C3 + 50C4 (see Figure 3.4 )
51A A-phase current above pickup setting 51AP for
A phase time-overcurrent element 51AT (see
Figure 3.15 )
Testing, Control
51AT A-phase time-overcurrent element 51AT timed out (see Figure 3.15 ) Tripping
51AR A-phase time-overcurrent element 51AT reset (see Figure 3.15 ) Testing
51B B-phase current above pickup setting 51BP for B phase time-overcurrent
element 51BT (see
Figure 3.16 )
Testing, Control
51BT B-phase time-overcurrent element 51BT timed out (see Figure 3.16 ) Tripping
6 51BR B-phase time-overcurrent element 51BT reset (see Figure 3.16 ) Testing
51C C-phase current above pickup setting 51CP for C phase time-overcurrent
element 51CT (see
Figure 3.17 )
Testing, Control
51CT C-phase time-overcurrent element 51CT timed out (see Figure 3.17 ) Tripping
51CR C-phase time-overcurrent element 51CT reset (see Figure 3.17 ) Testing
51P Maximum phase current above pickup setting 51PP
for phase time-overcurrent element 51PT (see
Figure 3.14 )
Testing, Control
51PT Phase time-overcurrent element 51PT timed out (see Figure 3.14 ) Tripping
51PR Phase time-overcurrent element 51PT reset (see Figure 3.14 ) Testing
51N Neutral-ground current (channel IN) above pickup setting 51NP
for neutral-ground time-overcurrent element 51NT (see
Figure 3.18 )
Testing, Control
7 51NT Neutral-ground time-overcurrent element 51NT timed out
(see
Figure 3.18 )
Tripping
51NR Neutral-ground time-overcurrent element 51NT reset (see Figure 3.18 ) Testing
51G Residual-ground current above pickup setting 51GP for residual-ground
time-overcurrent element 51GT (see
Figure 3.19 )
Testing, Control
51GT Residual-ground time-overcurrent element 51GT timed out
(see
Figure 3.19 )
Tripping
51GR Residual-ground time-overcurrent element 51GT reset (see Figure 3.19 ) Testing
51Q1
a
Negative-sequence current above pickup setting 51QP for negative-
sequence time-overcurrent element 51QT (see
Figure 3.21 )
Testing, Control
51QT
a
Negative-sequence time-overcurrent element 51QT timed out
(see
Figure 3.21 )
Tripping
51QR Negative-sequence time-overcurrent element 51QT reset
(see
Figure 3.21 )
Testing
Table 9.6 Relay Word Bit Definitions for SEL-351A (Sheet 2 of 16)
Row Bit Definition Primary Application
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