5 Mounting
Maschinenfabrik Reinhausen GmbH 2020
63
4983703/01 EN
VACUTAP
®
VV-Ex
5.4.5.2 Vapor-phase drying in the autoclave
For vapor-phase drying in the autoclave, you must open the kerosene drain
plug in the oil compartment base before drying so that the kerosene conden-
sate can drain from the oil compartment.
1. Unscrew kerosene drain plug in base of oil compartment counter-clock-
wise. The kerosene drain plug cannot be unscrewed all the way.
Figure 36: Kerosene drain plug
2.
NOTICE!
Remove the on-load tap-changer head cover (24 screws M10/
wrench size 17 with locking washers) and store it outside the autoclave. If
this is not done, the on-load tap-changer head cover may be damaged.
3.
NOTICE!
Remove on-load tap-changer accessories and store outside au-
toclave: motor-drive unit, drive shaft, protective relay, bevel gear, temper-
ature sensor. If this is not done, the on-load tap-changer accessories may
be damaged.
Vapor-phase drying in the autoclave
1. Supply kerosene vapor at a temperature of around 90°C. Keep this tem-
perature constant for 3 to 4 hours.
2. Increase the kerosene vapor temperature by approx. 10°C/hour to the de-
sired final temperature of max. 125°C at the on-load tap-changer.
3. Vacuum-dry on-load tap-changer at between 105°C and maximum 125°C
for at least 50 hours.
4. Residual pressure of no more than 10
-3
bar.
►
NOTICE!
Close kerosene drain plug clockwise (tightening torque 39 Nm).
An open kerosene drain plug leads to oil escaping from the oil compart-
ment and therefore to damage to the on-load tap-changer and trans-
former.
