Sel 411L - Page 656

P.9.10
SEL-411L Relay Protection Manual Date Code 20151029
Monitoring and Metering
Circuit Breaker Monitor
Set the Relay Word bits to respond to these inputs.
52AA1 := IN201. A-phase N/O Control Input—BK1 (SELOGIC Equation)
52AB1 := IN202 B-phase N/O Control Input—BK1 (SELOGIC Equation)
52AC1 := IN203 A-phase N/O Control Input—BK1 (SELOGIC 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,
respectively. 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) at 30 ms, and the slow close alarm threshold (B1MSCLT) at
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)
BM1CLSA := BK1CL OR IN304 Breaker Monitor A-phase Close—BK1
(SEL
OGIC Equation)
BM1CLSB := BK1CL OR IN305 Breaker Monitor B-phase Close—BK1
(SEL
OGIC Equation)
BM1CLSC := BK1CL OR IN306 Breaker Monitor C-phase Close—BK1
(SEL
OGIC Equation)
Assertion of the Relay Word bit B1MSOAL indicates any one of the
following four conditions:
➤ The mechanical operating time for a trip operation exceeds
30 ms (the slow trip alarm setting)
➤ The mechanical operating time for a close operation exceeds
70 ms (the slow close setting)
➤ No 52A1 status change occurred during the time B1MSTRT
plus approximately 100 ms after trip initiation (a trip time-out
condition)
➤ No 52A1 status change occurred during the time B1MSCLT plus
approximately 100 ms after close initiation (a close time-out
condition)
The relay makes a further check on the auxiliary circuit breaker (52A)
contacts by testing whether these circuit breaker contacts have changed state
within approximately 100 ms after the end of the trip or close threshold times.
Thus, this additional check serves as the trip time-out and close time-out
condition. This check verifies that the circuit breaker actually closed or
opened, and it alerts you if maintenance is required on the circuit breaker
mechanical linkages or auxiliary (52) contacts.
Electrical Operating Time
The electrical operating time is the time between trip or close initiation and an
open phase status change. For both circuit breakers, the relay measures the
tripping time for each phase from the assertion of the BM1TRP Relay Word