ABB UCG Series, Installation And Commissioning Manual

Page: 23 / 56

1ZSC000562-AAZ en | Installation and commissioning guide UCL/VUCL 23
3.2.3 Mounting on transformer cover (after the drying
process)
1. After the transformer cover is mounted, place the gasket
in the flange for the tap-changer. (This gasket is not
included
in the tap-changer delivery.)
Do not insert the studs for the upper flange in the
transformer cover flange. This is carried out at step 8.
2. Remove the locking device DS 4 from the drive shaft; see
Fig. 13.
CAUTION
Be careful not to drop the locking device and the
screw.
CAUTION
The drive shaft must not be rotated.
3. Place the O-ring in its groove in the lower flange; see
Fig. 11.
4. Place the upper flange over the opening in the transformer
cover. Turn the upper flange so that the flange for the
bevel gear is aligned with the drive shaft. The screws in
the lower flange must fit into the holes in the upper flange;
see Fig. 16.
5. Lift the tap-changer slowly until it just touches the upper
flange. Use lifting device LL 136 016-D. Attach the device
at the lower flange sides. The lifting device must be tilted
when attaching and removing; see Fig. 15.
6. When the flanges touch, fit twenty M8 locking nuts and
washers. Turn the nuts alternately until fully tightened.
Retighten all nuts to 24.5 Nm. After tightening the nuts,
remove the lifting device.
7. Place the O-ring for the bevel gear in its groove in the
upper flange; see Fig. 17. Remount the bevel gear unit in
the position it had before removal, and make sure that the
pin in the spherical shaft end fits into the drive shaft slot
without rotating the drive shaft. Secure the gear unit in the
flange with its four clamping screws M10x35 and washers.
CAUTION
The gear box must not be forced down. If the
coupling does not engage, lift the gear box and adjust
the setting of the drive pin.
8. Insert 24 studs; see Fig. 16, through holes in the upper
flange, down into the threaded holes in the flange of the
transformer cover. If the studs do not fit, the position of the
tap-changer must be adjusted, which may require lifting.
Lift by the lifting eyes as shown in Fig. 4. After mounting
the studs, remove the lifting device and tighten the nuts.
9. Mount the oil drainage tube; see Fig. 14. If a pipe wrench
is used, there must be cloth protection between the
wrench and the tube.
10. Mount the guide bar for the diverter switch; see Fig. 13. Fit
the washers and screws and tighten.
11. Remove the plug at the end of the T-coupling (see Fig. 18),
slide down the bottom valve key and close the valve by
turning the key clockwise approximately 6 turns. Tighten
to 40 Nm. Refit the plug.
12. Install the diverter switch according to Section 4.3.