Circuit breaker
type
Number of
years/closing
operations
(whichever
comes first)
SDV6
Five-years/
10,000 operation
Maintenance
Checks of primary power path
The primary power path consists of the
three vacuum interrupters, six bus
connections to the bushings and the roof-
mounted bushings. These components
must be checked for cleanliness and
condition. The vacuum interrupters must
also be checked for vacuum integrity.
Check torque of the bolts that secure the
roof bushings to the top plate of the circuit
breaker. Torque should be in the range of
20-25 ft-lbs (27-34 Nm).
Some test engineers prefer to perform the
contact erosion check during the manual
spring charging check of the operator,
since charging of the springs is necessary
to place the contacts in the close position.
Also, the vacuum integrity check is usually
performed in conjunction with the High
Potential tests. These instructions follow
the recommendation that these tests
contact erosion/manual spring charging
check, and vacuum integrity/high-potential
tests) will be combined as described.
Cleanliness check
Figure 8 is a side view of the type SDV6
distribution circuit breaker showing the
vacuum interrupter, bus connections and
roof bushings.
All of these components must be cleaned
and free of dirt or any foreign objects. Use
a dry lint-free cloth. For stubborn dirt, use
a clean cloth saturated with denatured
alcohol.
Also inspect the buswork for any evidence
of loose bolts, bushings for any evidence
of damage, and flexible connectors for
tightness and absence of mechanical
damage, burning, or pitting.
Checks of the stored-energy operator
mechanism
The stored-energy operator checks are
divided into mechanical and electrical
checks for simplicity and better
organization. The first series of checks
determine if the basic mechanism is clean,
lubricated and operates smoothly without
control power. The contact erosion check
of the vacuum interrupter is also
performed during these tasks.
Figure 8: Side view of type SDV6 distribution circuit breaker
Maintenance and lubrication
Table 4 presents the recommended
maintenance intervals for the type SDV6
distribution circuit breakers. These
intervals assume that the circuit breaker is
operated under "usual service conditions"
as discussed in ANSI/IEEE C37.04, section
4, and elaborated in ANSI/IEEE C37.010,
section 4. The maintenance and
lubrication interval is the lesser of the
number of closing operations or the time
interval since last maintenance.
Table 4: Maintenance and
lubrication intervals
Load side
2-4-6
Line side
1-3-5
Item
Description
A
Bushings
B
Bus
C
Vacuum interrupter
A
A
B
B
C
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