Schweitzer Engineering SEL-351P, Quick Start Manual

Page: 374 / 674

8-4 Breaker/Recloser Monitor, Battery System Monitor, Date Code 990430
Metering, and Load Profile Functions
SEL-351P Manual Técnico
Breaker Monitor Setting Example
If your recloser is not included in Table SECTION 8: .2, or you adapt the SEL-351P to operate a
breaker, you can create a contact wear monitor curve for your specific breaker or recloser. The
breaker/recloser contact wear monitor is set with breaker or recloser maintenance information
provided by circuit breaker and recloser manufacturers. This maintenance information lists the
number of close/open operations that are permitted for a given current interruption level.
The
following is an example of breaker maintenance information for a 25 kV circuit breaker.
Table SECTION 8: .4: Breaker Maintenance Information
for a 25 kV Circuit Breaker
Current
Interruption
Level (kA)
Permissible Number
of Close/Open
Operations*
0.0 - 1.2 10,000
2.0 3,700
3.0 1,500
5.0 400
8.0 150
10.0 85
20.0 12
*The action of a circuit breaker closing and
then later opening is counted as one
close/open operation.
The breaker maintenance information in Table SECTION 8: .4 is plotted in Figure SECTION 8:
.1.
Connect the plotted points in Figure SECTION 8: .1 for a breaker maintenance curve. To
estimate this breaker maintenance curve in the SEL-351P contact wear monitor, three set points
are entered:
Set Point 1 maximum number of close/open operations with corresponding current
interruption level.
Set Point 2 number of close/open operations that correspond to some midpoint
current interruption level.
Set Point 3 number of close/open operations that correspond to the maximum
current interruption level.
These three set points are entered with the settings in Table SECTION 8: .1.