IL
44-751-1
Instruction
Leaflet
Page 13 November, 2001
NOTE: Make sure that the Nylock bolt has a blue Nylon patch near the bottom end. This patch
provides anti rotational locking and prevents the bolt from becoming loose. If this bolt assembly
is removed, a new Nylock bolt should be used to insure this positive locking action is maintained
.
NOTE: If the DTW decks are mounted to the superstructure as described in Step 2, it will be
necessary to loosen the nuts for at least the second phase to be able to fit the Inter-phase shafts.
Figure 17. Nylock Screw, Creep washer, cup washer and lock washer
for assembly of Inter-phase Shaft to ball end fitting of a DTW.
6. Fit the second DTW deck to the Inter-phase shaft mounted in Step 5 and then repeat Steps
3, 4 and 5 for this deck. NOTE: Make sure that the moving contact of the first and the second
deck are both in position number 1, when connecting the shaft.
7. Fit the third DTW deck to the Inter-Phase Shaft of the second deck and repeat Steps 3, 4
and 5 for this deck. NOTE: Make sure that the moving contact of the first, second and third
decks are all in the number 1 position, when connecting this shaft.
8. Mount the Drive Shaft to the DTW at the appropriate end (Left or Right) as specified on the
transformer drawings. The drive shaft is assembled to the ball end fitting in the same way as
the Inter-Phase Shafts. NOTE: Make sure that the two Spring pins at the end of the Drive
Shaft are undamaged. Proper operation of these pins is necessary for proper operation of
the tap changer.
9. If electrostatic shielding kits are to be used, they should be mounted at this time.
10. To install a Level 1 shield kit, bolt the crepe paper wrapped aluminum shield casting /
aluminum mounting disk to the worm gear housing with the three bolts provided in the kit.
NOTE: Make sure that the top mounting bolt holding the aluminum casting to the gear
housing does not make contact with, nor interfere with the gear, See Figure 18.
11. To install a Level 2 shield kit bolt the crepe paper wrapped aluminum shield casting /
aluminum mounting disk to the worm gear housing with the three bolts provided in the kit as
in Step 10. The outer continuous ring shield is put in position and, after that, the inner half-
circle ring shields are put in position. Both the outer ring and the inner half-circle rings are
bolted to the cast aluminum-mounting
disc with a total of four bolts. See Figure 19.
