12. Position the interrupter with the slot in the moving ter-
minal uppermost and slide the moving terminal through
the plastic support ring on the large polehead. Move
the stationary end of the interrupter (with copper spacer
when so equipped) into position on the small polehead
and install the cap screw(s) (may be three or one de-
pending on design) into the interrupter finger tight only.
13. Check the end of the interrupter at the large polehead to
be sure that the body of the interrupter is supported in
the plastic ring. This is a snug fit and may require a
slight twisting motion.
14. Torque fastener(s) at the interrupter stationary contact
to firm the interrupter stationary contact against the small
polehead, using torque shown in Table 7
.
The compan-
ion lock washer is to be fully collapsed. Hold interrupter
in the alignment required under Step 11 of vacuum in-
terrupter replacement procedure while tightening this
fastener(s).
15. Slip the flexible shunt clamp over the movable contact
stem of the interrupter. Care must be taken to avoid ap-
plying any twisting or bending forces to the movable
contact stem as this could cause premature bellows fail-
ure. Replace clamp hardware; bolt(s), washer(s), and
nut(s). Position the clamp firmly against the shoulder
on the terminal and tighten hardware firmly. Check to
be sure the shunt clamp is positioned vertically and has
adequate clearance on both sides. If the clamp is tilted,
reposition vertically and retighten using torque shown
in Table 7
.
16. Thread the jam nut onto the rod end bearing as far as it
will go, and then screw the rod end bearing into the mov-
ing terminal approximately half way. Do not tighten at
this time.
17. Place a 0.250 inch drill rod or No. 2 Phillips screwdriver
through the rig pin hole in the side of the polehead. Pass
the rod through the slots in the levers and then through
the rig pin hole in the opposite side of the polehead. This
locks the levers in a fixed position for adjusting the drive
mechanism.
18. Push the small pin removed in Step 4 through the open
hole in a lever, through the rod end bearing, and through
the other lever. If the holes do not line up to permit this,
the rod end bearing must be screwed in or out until the
pin passes freely through both levers and the rod end
bearing. Use care in this adjustment. The pin must pass
through all three holes with a light pressure by hand.
19. Maintain the position of the rod end bearing while tight-
ening the jam nut against the terminal end using torque
shown in Table 7. When properly installed, the rod end
bearing will be in a vertical position.
20. Remove the small pin and reassemble with the spacers
and snap rings removed in Step 4. Be sure the snap
rings are firmly seated in their grooves. Replace the rings
if they are bent or feel loose after installation.
21. With the 0.250 inch drill rod in place, push the coupling
rod assembly into firm contact with the operating levers.
While maintaining this position, check to see that the
top of the coupling rod (bottom of pivot block) is flush
with the top of the operating levers. This is the correct
adjustment of the coupling rod.
22. If the coupling rod (pivot block) is higher or lower than
the top of the operating levers, the coupling rod must be
readjusted. Locate the LOWER end of the coupling rod,
where it attaches to the operator jackshaft levers. The
threaded stud of the coupling rod passes through a
threaded hole in the jackshaft lever pin, and has a jam
nut above and below the lever pin. Loosen the upper
and lower jam nuts to permit the rotation of the cou-
pling rod. These parts have been assembled using a
threadlocking adhesive and will have some resistance
to turning.
23. Adjust the coupling rod as follows:
a. If the coupling rod extends above the top surface of
the operating levers, turn the coupling rod clockwise
until the surfaces are flush.
b. If the coupling rod is below the top surface of the op-
erating levers, turn the coupling rod counterclockwise
until the surfaces are flush.
c. Apply fresh serviceable threadlocking adhesive Loctite
242 to the threads between the jam nuts and the
jackshaft pin. Tighten the jam nuts securely.
24. Remove the drill rod from the large polehead.
25. Twist the pivot block so that the axis of the block pins
approach the axis of the lever holes at approximately
45
°
. Manually raise the levers. When the lever hole is
aligned with the most forward pin, push on the coupling
rod to lock that lever in position. Apply pressure while
prying the other lever outward to pass over the other
pin. As the last pin passes between the levers, the first
pin will snap into its hole. The second lever may have to
be raised or lowered to align with its hole. Replace the
snap rings on the ends of the pivot block pins.
26. This completes the installation and adjustment of the
interrupter. Operate the breaker manually several times
and recheck all fasteners to assure that they are prop-
erly installed or tightened.
27. Replace the phase barriers (when so equipped) removed
in Step 2.
28. Perform High Potential Test across open vacuum inter-
rupter and from each primary connection to ground (See
Table 4 on page 26).
Note: Check to be certain the interrupter clamp has
been positioned against the movable stem step
before securing the clamp.
Overhaul
36
