5 Mounting
Maschinenfabrik Reinhausen GmbH 2020
62
4983703/01 EN
VACUTAP
®
VV-Ex
5.4.5 Drying on-load tap-changer in autoclave
NOTICE
Damage to the on-load tap-changer!
Moisture in the oil compartment reduces the dielectric strength of the insu-
lating fluid and thus leads to damage to the on-load tap-changer.
► Within 10 hours of drying, seal off oil compartment with on-load tap-
changer head cover.
Dry on-load tap-changer in accordance with the following instructions to en-
sure the dielectric values assured by MR for the on-load tap-changer.
If drying in an autoclave, the following methods are possible:
▪ Vacuum drying
▪ Vapor-phase drying
As an alternative to drying the on-load tap-changer in an autoclave, it can
also be dried in the transformer tank.
5.4.5.1 Vacuum-drying in the autoclave
Before starting vacuum-drying in the autoclave, you must remove the on-
load tap-changer head cover and on-load tap-changer accessories:
1.
NOTICE!
Remove the on-load tap-changer head cover (24 screws M10/
wrench size 17 with safety elements) and store it outside the autoclave. If
this is not done, the on-load tap-changer head cover may be damaged.
2.
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.
Vacuum-drying in the autoclave
1. Heat up the on-load tap-changer in air at atmospheric pressure with a
temperature increase of approximately 10 °C/h to a final temperature of
maximum 110 °C.
2. Pre-dry the on-load tap-changer in circulating air at a maximum tempera-
ture of 110 °C for a period of at least 20 hours.
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.
Содержание VACUTAP VV-Ex
Страница 1: ...On load tap changer VACUTAP VV Ex Installation and commissioning instructions 4983703 01 EN ...
Страница 135: ...9 Drawings Maschinenfabrik Reinhausen GmbH 2020 135 4983703 01 EN VACUTAP VV Ex 9 Drawings 9 1 External view 737774 ...
Страница 138: ...9 Drawings Maschinenfabrik Reinhausen GmbH 2020 138 4983703 01 EN VACUTAP VV Ex 9 4 Installation drawing 738902 ...
Страница 139: ...9 Drawings Maschinenfabrik Reinhausen GmbH 2020 139 4983703 01 EN VACUTAP VV Ex 9 5 Oil suction pipe 739172 ...
Страница 142: ...9 Drawings Maschinenfabrik Reinhausen GmbH 2020 142 4983703 01 EN VACUTAP VV Ex 9 8 Mounting drawing 898866 ...
Страница 149: ......