Siemens 3AH3 Instruction Manual page 46

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2.8 Align pole head (20.0) correctly and
tighten bolt fastening it to the post
insulator. Torque M16 bolt to 130 Nm
(96 ft-lb). Fasten securely all bolts
associated with struts (28.0).
2.9 Tighten vacuum interrupter fastening
bolt (31.2) on the pole head (20.0)
holding the vacuum interrupter firmly
by its upper insulator and operate
levers (48.6), by hand, to see whether
the movable contact moves freely. If
any binding or lack of freedom is
noted, loosen bolt (31.2) and adjust
the vacuum interrupter in pole head by
turning and moving it slightly. Torque
M12 bolt to 60 Nm (44 ft-lb) and M16
bolt to 130 Nm (96 ft-lb).
2.10 The centering ring (28.1) has been
loose and "floating" during installation
of the vacuum interrupter. Check that
the movable contact is free to move
vertically without binding, and then
tighten the hardware which secures
the centering ring. Recheck that the
movable contact is free to move
vertically without binding.
2.11 Attach insulating coupler (48.0) and
lever (48.6) together, using pin (48.5).
Apply retaining clips. Correct pin has
ends that have been generously
chamfered.
2.12 Open and close circuit breaker several
times and then check to see that all
bolted joints and devices are tight.
3. Checking the contact stroke
3.1 Open the circuit breaker.
3.2 Free insulating coupler (48.0) by
removing pin (48.5). The vacuum
interrupter contacts must now close
automatically as a consequence of
atmospheric pressure.
3.3 Observe the terminal clamp (29.2)
through the openings on each side of
the pole bottom (40.0). Using vernier
calipers, measure the distance from the
bottom surface of the terminal clamp
to the bottom edge of the cutout
opening. Measure carefully and record
your result.
3.4 Connect the insulating coupler (48.0)
using pin (48.5) and the retaining clips
provided.
3.5 Repeat the measurement described in
step 3.3 again with care to maximize
accuracy. Record your result.
3.6 Determine difference between the
measurements made under steps 3.3
and 3.5. Your results should be per
Table 7.
3.7 If you fail to achieve the listed results,
carefully repeat the entire procedure
making certain of your measurements.
3.8 Loosen eye bolt locking nut on
insulating coupler (48.0), and retain
position of the eye. Make adjustments
in one-half turn increments. After
adjustment is completed, tighten eye
bolt locking nut to 26-34 ft-lb. (35-45
Nm).
4. After eye bolt is tightened to proper
torque, repeat all measurement
procedures, making certain they are in
agreement with values indicated in
step 3.6.
5. Complete all other maintenance
procedures. Completely reassembled
circuit breaker should pass the high-
potential test before it is ready for
service.
Hydraulic shock absorber
The mechanism is equipped with a hydraulic
shock-absorber that functions when the
circuit breaker opens (refer to item 61.8 in
Figure 6). The shock absorber should require
no adjustment. However, at maintenance
checks, the shock absorber should be
examined for evidence of leaking. If
evidence of fluid leakage is found, the shock
absorber must be replaced to prevent
damage to the vacuum interrupter bellows.