• Checks Of The Pri M A Ry Power Path; • Clean L Iness Check; • I Nspection Of Flexible Connectors; Checks Of The Stored Energy Operator Mechanism - Siemens 3AH Series Instructions Manual

Maintenance
Table 1 Maintenance Tasks
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• Checks of the pri m a ry power path
• Clean l iness check
• I nspection of flexible connectors

Checks of the stored energy operator mechanism

• Maintena n ce and l u brication
• Fastener check
• M a n u a l spring charging check
• Contact erosion check
• Electrical control checks
• Wiring a n d terminals check
• Secondary disconnect check
• Automatic spring charg ing check
• Electrical close and trip check
• Vacuum integrity check
• High potenti a l test
• Insu lation test
• Contact resistance test
• I nspection a n d cleaning of circuit breaker insulation
• Functional tests
The l i st of tasks in Table 1 does not represent an exha us­
tive su rvey of m aintenance steps n ecessary to ensure safe
operation of the equi pment. Particular a pplications may
requ i re further p roced ures. Should further information be
desired or should particular problems arise which are not
covered sufficiently for the Purchaser's pu rposes, the matter
should be referred to the local Siemens sales office.
DANGER
A
The use of unauthorized parts in the repair of the equip­
ment, or tampering by unqualified personnel will result in
dangerous conditions which will cause death, serious injury
or equipment damage.
Follow all safety instructions contained herein.
Checks of the Primary Power Path
The primary power path consists of the three vacuum inter­
ru pters, the three u pper and the three lower primary discon­
nects. These components are checked for cleanliness a n d
condition. The vacuum i nterrupters a r e also checked for
vacu u m integrity.
Some test engineers prefer to perform the contact erosion
check during the m a n u a l spring charg i n g check of the opera­
tor, since charging of the springs is necessary to place the
contacts in the closed position.
Also, the vacu u m integrity check is usually performed in
conj u n ction with the High Potential tests.
These instructions follow the recommendation that these
tests (contact erosion/manual spring charging check, and
vacuum integrity/h igh potential tests) will be combined as
described.
Cleanliness Check
Figure 2 is a side view of the circuit breaker with the insu­
lating barriers removed (if furnished) to show the vacu u m
interru pter, and t h e upper and lower connection pad.
All of these components must be clean and free of dirt or a ny
foreign objects. Use a dry l int-free cloth. For stubborn d i rt,
use a clean cloth saturated with denatured alcohol (except
for the vacuu m interrupters ) . For stubborn dirt on a vacu u m
interrupter u s e a d a m p cloth a n d then thoroughly d ry i t using
a d ry l int-free cloth.
Inspection of Flexible Connectors
Inspect the flexible connectors that connect the bottom
movable contacts of the vacu u m interrupters to the lower
connection pad for tightness and absence of mech a n ical
damage, burning, or pitting.
Checks of the Stored Energy Operator Mechanism
The stored energy operator checks a re divided into mechani­
cal a n d electrical checks for simplicity a n d better organ iza­
tion. Th is first series of checks determine if the basic mecha­
nism is clean, l ubricated and operates smoothly without
control power. The contact erqsion check of the vacuum
interrupter is a l so performed d uring these tasks.
Maintenance and Lubrication
Table 2 Maintenance and Lubrication Intervals (ANSI
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C37.06) Usual Service Conditions M aintenance Based U pon
N umber of Circuit Breaker Closing Operations.
Circuit Breaker T ype
kV
kA (MVA)
5 kV 36kA (250MVA)
15 kV 23kA (500MVA)
All Others All Others
Note: For circuit breaker rati ngs other than 5kV - 250MVA
and 1 5kV - 500MVA overh a u l is required at 10,000 operations
refe rence Overha u l Section.
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The vacu um interrupter operator mech anism is shown in
Figure 1 5 with the front cover removed to show construction
details. Both the opening spring and the closing spring a re
shown . The movable end of the closing spring is connected
to a cra n k arm. The movable end of the opening spri n g is
connected to the jack shaft by a pull rod.
Clean the entire stored energy operator mechanism with a
dry, lint-free cloth.
Check all components for evidence of excessive wear. Place
special attention upon the closing spring crank and the insu­
lating couplers and l i n kages.
Lu bricate a l l non-electrical moving or sliding s u rfaces with a
light coat of synthetic g rease or oil. Lubricants composed of
ester oils and lith i u m thickeners will be compatible.
Shell ( d rawn cup) needle bearings:
Use either Klueber lsoflexTopas L32 ( reference 3AX11 333H)
Anderol 732 ( reference 1 5-1 72-81 6-058) or Beacon ( Exxon
325 (reference# 1 8-658-676-422, pa rt # 1 5-337- 1 3 1-001 ) .
Pivots, sliding, and/or rolling surfaces and general l ubrication:
Use either Klueber lsoflexTopas L32 (reference 3AX11 333H)
Anderol 732 ( reference 1 5-1 72-81 6-058) or Beacon (Exxon
325 (reference# 1 8-658-676-422, part # 1 5-337- 1 3 1 -001 ) .
Number of
Years/Closing Operations
10 years/10,000 operations
10 years/10,000 operations (See Note)
20