45
1.5 Free struts (28.0) from the pole head
(20.0). Loosen the strut hardware on
the moving-end pole head (40.0) and
swing the struts (28.0) away from the
vacuum interrupter.
1.6 Loosen screws fastening the centering
ring (28.1).
1.7 Remove bolt (31.2), lock washer and
large washer at the stationary contact
end of the vacuum interrupter (18 mm
or 24 mm socket with extension).
1.8 Using a 24 mm socket with an
extension, loosen and remove hex-cap
screw fastening the fixed-end pole
head (20.0) to the post insulator
(16.1). Completely remove the fixed-
end pole head (20.0) and set aside.
1.9 Grasp the vacuum interrupter (30.0)
and withdraw horizontally. Assistance
may be required to work the terminal
clamp off the movable stem of the
vacuum interrupter.
Note:
DO NOT USE UNDUE FORCE OR
TWISTING MOTION. If the terminal clamp
(29.2) cannot be easily removed, STOP!,
check to be certain hardware is loose, and
that the terminal clamp (29.2) is not
binding.
2. Installing a vacuum interrupter
Note:
Replacement vacuum interrupter
(30.0) will be received from the factory with
an eye bolt (36.3) in place, adjusted and
torqued to specific requirements. DO NOT
ALTER THE ADAPTER (EYE-BOLT) SETTING.
2.1 Inspect all silver-plated connection
surfaces for cleanliness. Clean only
with a cloth and solvent. Do not
abrade, as this will damage the silver
plating.
2.2 Insert vacuum interrupter (30.0) into
the moving-end pole head (40.0). Slip
terminal clamp (29.2) into position on
the movable stem.
2.3 Fasten the fixed-end pole head (20.0)
to the post insulator (16.1) “finger
tight” using hex-head bolt, lock washer
and flat washer.
2.4 Align vacuum interrupter and fasten
“finger tight” to the fixed-end pole
head (20.0) using heavy flat washer,
lock washer and bolt (31.2).
2.5 Attach struts (28.0) to the fixed-end
pole head (20.0), replace hardware
(M10), but do not tighten at this time.
2.6 Couple levers (48.6) and drive link
(48.9) to the eye bolt (36.3), using the
pin supplied. Apply retaining clips.
Appropriate pin is modestly chamfered,
not to be confused with pin for the
insulating coupler.
2.7 Align fixed-end pole head (20.0)
correctly and tighten bolt fastening it
to the post insulator (16.1). Torque
M16 bolt to 130 Nm (96 ft-lb). Fasten
securely all bolts associated with struts
(28.0).
2.8 Tighten vacuum interrupter fastening
bolt (31.2) on the fixed-end pole head
(20.0) holding the vacuum interrupter
firmly by its fixed-end 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 the fixed-end
pole head (20.0) by turning and
moving it slightly. Torque M12 bolt to
60 Nm (44 ft-lb) and M16 bolt to 130
Nm (96 ft-lb).
2.9 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
axially without binding, and then
tighten the hardware which secures
the centering ring (28.1). Recheck that
the movable contact is free to move
axially without binding.
2.10 Move the terminal clamp (29.2)
against the step or the spacer (if
applicable) of the moving contact
(36.1) of the vacuum interrupter (30.0)
so that the recess of the movable
contact faces the connecting surface of
the flexible connector (29.1). Employ
technique illustrated to fasten terminal
clamp (refer to Figure 25: Illustration
showing required technique for
fastening terminal-clamp hardware on
page 47). Note opposing wrenches.
Tighten the bolt(s) of the terminal
clamp to a torque of 40 Nm (30 ft-lb),
taking care to see that the terminal of
the vacuum interrupter is not subjected
to excessive bending movement.
