Schweitzer Engineering Laboratories SEL-421-4 - Page 1048

8.10
SEL-400 Series Relays Instruction Manual Date Code 20171006
Monitoring
Circuit Breaker Monitor
Figure 8.5 Mechanical Operating Time for Circuit Breaker 1 A-Phase
Example 8.5 Mechanical Operating Time Settings
Use Circuit Breaker 1, a single-pole tripping circuit breaker, for this exam-
ple. Connect the circuit breaker normally open 52A contacts through station
battery power to IN201, IN202, and IN203. This example uses inputs IN201,
IN202, and IN203 for A-, B-, and C-Phases, respectively; you can use any
control inputs that are appropriate for your installation. The control voltage
for this example is 125 Vdc.
Control Inputs IN201–IN203 are direct-coupled inputs.
Set the Relay Word bits to respond to these inputs.
52AA1 := IN201 A-Phase N/O Control Input—BK1 (SEL
OGIC Equation)
52AB1 := IN202 B-Phase N/O Control Input—BK1 (SEL
OGIC Equation)
52AC1 := IN203 A-Phase N/O Control Input—BK1 (SEL
OGIC Equation)
Connect external trip signals to IN301, IN302, and IN303, and external close
signals to IN304, IN305, and IN306 for the A-, B-, and C-Phases, respec-
tively. Use the default settings for input conditioning (debounce time and
assertion level), as with inputs IN201 to IN203 above.
Set the mechanical operating time threshold for the slow trip alarm
(B1MSTRT) to 30 ms, and the slow close alarm threshold (B1MSCLT) to
70 ms. Use your company standard practices to determine these settings for
your application. For this example, enter the following settings:
B1MSTRT := 30 Mechanical Slow Trip Alarm Threshold—BK1
(1–999 ms)
B1MSCLT := 70 Mechanical 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 IN301 Breaker Monitor A-Phase Trip—BK1
(SEL
OGIC Equation)
BM1TRPB := TPB1 OR IN302 Breaker Monitor B-Phase Trip—BK1
(SEL
OGIC Equation)
BM1TRPC := TPC1 OR IN303 Breaker Monitor C-Phase Trip—BK1
(SEL
OGIC Equation)
BM1TRPA
(A-Phase Trip)
52AA1
Mechanical Tripping Time
BM1CLSA
(A-Phase Close)
52AA1
Mechanical Closing Time