Preparations; Planning; Required Tools; Consumables - ABB VUBB User Manual

3 Preparations

3.1 Planning

To shorten the down-time when doing maintenance, it is important to plan the work so that waiting time is
minimized. Thus, when the tap-changer is oil-filled with the atmospheric process, work should be completed
on the tap-changer before work is started on the motor-drive. So that the waiting time requirement is satisfied
as soon as possible.
Oil-filling process
Atmospheric
Vacuum
The atmospheric oil-filling process
Some waiting time is necessary after the tap-changer has been oil-filled, before it is energized. The reason for
this is that air bubbles stick to the surfaces inside the tap-changer when it is filled with oil, and flashovers and
partial discharges can form in the bubbles. Thus, it is important to let the necessary waiting time pass, to
make sure that all the air bubbles have risen to the surface of the oil before the tap-changer is energized.

3.2 Required tools

Tool
Standard set of open-end
wrenches
Standard set hex-keys
Ratchet wrench handle with
extension
Oil sampling container
Test equipment
Protective gloves

3.3 Consumables

Item
Transformer oil
Lubrication oil
GULF-718 EP
Aero Shell Grease 22
User guide
1ZSC000562-AAL EN, REV. B, 2020-03-18
Article number
-
-
-
-
-
-
Brand Part number
- -
- -
Gulf -
Shell -
Minimum required waiting time
3 hours
Waiting time not necessary
Note
9/16" is used.
3/8" is used.
-
-
IEC 60156, IEC 60475
Oil-resistant
Note
Volume approximately 270 liter.
• Complies with
IEC 60296-LCSET.
• Electrical withstand
requirement
>40 kV@ 2.5 mm gap,
according to IEC 60156.
For bearings.
For ball-bearings.
For shaft system.
13