30
1ZSE 5492-129 en, Rev. 6
3. Repairs and adjustment
3.4 Replacement or addition of a multi-position switch (BUL only)
3.4.1 General
Addition of a multi-position switch as described below is possible when you have 1, 2, or 4
multi-position switches. In other cases the shaft must also be exchanged and ABB should
be contacted for further instructions.
3.4.2 Tools Required
■
Small wrench (10 mm)
3.4.3 Procedure
WARNING
Before starting any work inside the motor-drive mechanism, the auxiliary power must
be switched off.
N.B. The motor, contactors and heating element may be energized from separate
sources.
1. Dismantle the bottom plate, see Fig. 10 on next page.
For replacement also remove necessary distance screws and multi-position switches,
and their conductors.
2. For addition exchange the lower distance screws to new ones, length 20 and 10 or
35 mm.
3.
Turn the contact arm on the new multi-position switch to the same position as the exist-
ing multi-position switches. Place the transparent cover on the multi-position switch
and push it all on the shaft. The nob in the hub of the multi-position switch must enter
the groove in the shaft.
4.
Reassemble washers and distance screws. Press up the shaft and make sure the notch
on the couplings have entered the grooves in the torque disc. Press down the sliding
bearing in the bottom plate and assemble the bottom plate. Check that there is no axial
play in the shaft. If necessary washers may be removed or added.
5.
Note the position of the on-load tap-changer. Operate the the motor-drive mechanism
in all positions both in raise and lower directions and check with a buzzer that all multi-
position switches function properly.
6.
Connect the terminals.
7.
Reconnect all power supplies to the motor-drive.
8. Operate it back to the position noted in point 5.
