Cover-Mounting; Ucc With Tap Selector Size - ABB UCC Series Installation And Commissioning Manual

3.1 Cover-Mounting

(For Yoke-Mounting, see section 3.2).
The diverter switch housing and tap selector are delivered packed separately.
3.1.1 UCC with Tap Selector size IV
1. Unpack the diverter switch housing and the tap selector. Remove the drying agents
and the yellow cushions with vapour phase inhibitor for protection against
corrosion in the tap selector and on the diverter switch housing.
2. Fit the gasket into the on-load tap-changer flange on the transformer cover, see
Fig. 5. (This gasket is not included in the delivery).
3. When the impulse withstand voltage to earth exceeds 380 kV, the on-load
tap-changer is provided with shielding rings. Before mounting the diverter switch
housing on the transformer cover two shielding rings must be dismantled, see
Fig. 7.
UCC, UCD
diverter switch
Opening in the
transformer cover
Selector size III,
IV and G
fm_00222
3 Installation in the Transformer
Gasket Nut M16 (30x)
Washer (30x)
Stud M16
Transformer
top cover
TC_00067