![Schweitzer Engineering Laboratories SEL-421-4 Instruction Manual Download Page 476](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_1216726476.webp)
6.140
SEL-421 Relay
Instruction Manual
Date Code 20171021
Protection Applications Examples
Autoreclose Example
Enable the voltage check elements.
EVCK :=
Y
.
Reclosing Voltage Check (Y, N)
Set the dead line voltage threshold equal to 15 V secondary.
27LP :=
15.0
.
Dead Line Voltage (1.0–200 V secondary)
Set the live line voltage threshold equal to 50 V secondary.
59LP :=
50.0
.
Live Line Voltage (1.0–200 V secondary)
Set the dead bus voltage threshold for Circuit Breaker 1 equal to 15 V secondary.
27BK1P :=
15.0
.
Breaker 1 Dead Busbar Voltage (1.0–200 V secondary)
Set the live bus voltage threshold for Circuit Breaker 1 equal to 50 V secondary.
59BK1P :=
50.0
.
Breaker 1 Live Busbar Voltage (1.0–200 V secondary)
Example Complete
This completes the application example that describes setting the SEL-421 for
one shot of three-pole reclosing for a single circuit breaker. Analyze your partic-
ular power system to determine the appropriate settings for your application.
Relay Settings
provides a list of all the SEL-421 autoreclose settings. Those settings
that were applied for this particular application appear in boldface.
Figure 6.36
Potential Sources
SEL-421
1
3
Line
Disconnect
(Line Potential)
(Bus Potential)
VAZ
VY
BK1
Table 6.39
Settings for Autoreclose Example (Sheet 1 of 2)
Setting
Prompt
Entry
Relay Configuration
E79
Reclosing (Y, Y1, N)
Y
Recloser Closing (Group)
NSPSHOT Number of Single-Pole Reclosures (N, 1, 2)
N
N3PSHOT Number of Three-Pole Reclosures (N, 1–4)
1
E3PR1
Three-Pole Reclose Enable—BK1 (SEL
OGIC
Equation)
IN106
BKCFD
Breaker Close Failure Delay (OFF, 1–99999 cycles)
600
ULCL1
Unlatch Closing for Breaker 1(SEL
OGIC
Equation)
52AA1
79DTL
Recloser Drive to Lockout (SEL
OGIC
Equation)
LOP
79BRCT
Block Reclaim Timer (SEL
OGIC
Equation)
NA
Summary of Contents for SEL-421-4
Page 6: ...This page intentionally left blank ...
Page 14: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 104: ...This page intentionally left blank ...
Page 128: ...This page intentionally left blank ...
Page 536: ...This page intentionally left blank ...
Page 584: ...This page intentionally left blank ...
Page 616: ...This page intentionally left blank ...
Page 696: ...This page intentionally left blank ...
Page 750: ...This page intentionally left blank ...
Page 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Page 776: ...This page intentionally left blank ...
Page 932: ...This page intentionally left blank ...
Page 976: ...This page intentionally left blank ...
Page 1024: ...This page intentionally left blank ...
Page 1038: ...This page intentionally left blank ...
Page 1064: ...This page intentionally left blank ...
Page 1128: ...This page intentionally left blank ...
Page 1206: ...This page intentionally left blank ...
Page 1316: ...This page intentionally left blank ...
Page 1350: ...This page intentionally left blank ...
Page 1464: ...This page intentionally left blank ...
Page 1468: ...This page intentionally left blank ...
Page 1492: ...This page intentionally left blank ...
Page 1518: ...This page intentionally left blank ...