![Schweitzer Engineering Laboratories SEL-421-4 Instruction Manual Download Page 1050](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_12167261050.webp)
8.12
SEL-400 Series Relays
Instruction Manual
Date Code 20171006
Monitoring
Circuit Breaker Monitor
Primary load/fault current can indicate contact closing, contact opening, and arc
extinction, depending upon the actual circuit breaker monitor setup. You can
detect problems within the circuit breaker arcing chamber by timing the interval
from trip/close initiation to electric arc extinction.
Figure 8.6
Electrical Operating Time for Circuit Breaker 1 A-Phase
Example 8.6
Electrical Operating Time Settings
Use Circuit Breaker 1, a single-pole tripping circuit breaker, for this exam-
ple. Connect external trip signals to IN201, IN202, and IN203, and external
close signals to IN204, IN205, and IN206 for the A-, B-, and C-Phases,
respectively. This example uses control inputs IN201–IN206; you can use
any control inputs that are appropriate for your installation. The control volt-
age for this example is 125 Vdc.
Control Inputs IN201–IN206 are located on the relay I/O Interface board #1.
Set the electrical operating time threshold for the slow trip alarm (B1ESTRT)
at 25 ms, and the slow close alarm threshold (B1ESCLT) at 65 ms. Use your
company standard practices to determine these settings for your application.
For this example, enter the following settings.
B1ESTRT :=
25
Electrical Slow Trip Alarm Threshold—BK1 (1–999 ms)
B1ESCLT :=
65
Electrical Slow Close Alarm Threshold—BK1 (1–999 ms)
EB1MON :=
Y
Breaker 1 Monitoring (Y, N)
BK1TYP :=
1
Breaker 1 Trip Type (Single Pole = 1, Three Pole = 3)
BM1TRPA :=
TPA1 OR IN201
Breaker Monitor A-Phase Trip—BK1
(SEL
OGIC
Equation)
BM1TRPB :=
TPB1 OR IN202
Breaker Monitor B-Phase Trip—BK1
(SEL
OGIC
Equation)
BM1TRPC :=
TPC1 OR IN203
Breaker Monitor C-Phase Trip—BK1
(SEL
OGIC
Equation)
BM1CLSA :=
BK1CL OR IN204
Breaker Monitor A-Phase Close—BK1
(SEL
OGIC
Equation)
BM1TRPA
(A-Phase A Close)
A-Phase Open
A-Phase Open
Electrical Closing Time
BM1CLSA
(A-Phase A Trip)
Electrical Tripping Time
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 ...