Siemens vacuum circuit breaker 38-3AH3 38 kV - Manual (Page 54)

Overhaul
D. Solenoid mounting screws must be
installed using thread locking
adhesive (Loctite #222, Siemens
part 15-133-281-007) and primer
(Loctite primer T, Siemens part 15-
133-281-005).
E. Connect wires to coils with new
"push on" wire terminals (Siemens
part 15-171-600-002).
3. Lubricate operating mechanism in
accordance with instructions that
follow.
4. When work is finished, operate circuit
breaker, close/open several times, and
check that all screw connections are
tight.
Vacuum interrupter replacement
It is recommended that vacuum
interrupters be replaced only by a qualified
Siemens representative. The information in
the following sections is provided to aid in
understanding the replacement
procedures.
Replacement vacuum interrupters are
furnished as a complete assembly, and
have been completely tested and
mechanically conditioned.
It is recommended one vacuum interrupter
be removed and replaced completely
rather than removing two or more vacuum
interrupters at a time.
The following procedure describes the
procedure for removing and replacing a
vacuum interrupter. Components may be
identified by referencing Figure 46:
Vacuum interrupter replacement
illustration on page 56 and Figure 47:
Illustration showing required technique for
fastening terminal-clamp hardware on
page 57.
Note: Special care needs to be exercised in
removal or installation of hardware around
the bottom, or movable contact end, of
the vacuum interrupter.
The movable contact uses a metal bellows
to maintain the vacuum seal while still
permitting up and down motion of the
contact. This metal bellows is rugged and
reliable, and is designed to withstand years
of vertical movement. However, care
should be exercised to avoid subjecting the
metal bellows to excessive torque during
removal and replacement. Twisting the
metal bellows through careless bolt
removal or tightening may damage the
vacuum interrupter.
1.0 Removing the vacuum interrupter
1.1 Before starting work, the circuit
breaker should be isolated from all
primary- and control-power sources
and all stored energy discharged by
tripping, closing and tripping the
circuit breaker by hand. Discharge any
static charge by grounding both ends
and the center metal section of the
vacuum interrupter. Carefully remove
outer-phase and inter-phase barriers.
1.2 Loosen the lateral bolt(s) on terminal
clamp (29.2). Refer to Figure 47:
Illustration showing required
technique for fastening terminal-
clamp hardware on page 57 and
employ the illustrated procedure to
loosen clamp hardware (6 or 8 mm
hex-key and 13 or 16 mm socket).
1.3 Withdraw pin (48.5) from insulating
coupler (48.0) and levers (48.6).
1.4 Remove coupling pin from the eye
bolt (36.3).
1.5 Free struts (28.0) from the upper
pole-support (20.0). Loosen the strut
hardware on the lower support (40.0)
and swing the struts forward and
downward (16 mm open-end wrench
and 16 mm socket).
1.6 Loosen screws that secure the
centering ring (28.1) (10 mm open-
end wrench).
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