ABB VUCG.N - Type of Regulation; Linear Switching (Type L); Change-Over Selector for Plus;Minus Switching (Type R); Change-Over Selector for Coarse;Fine Switching (Type D)

16 Technical guide VUC | 1ZSC000562-AAX en, Rev. 1
Type of regulation
Linear switching (type L)
The regulating range is equal to the voltage of the tapped
winding. No change-over selector is used. Fig. 28.
Fig. 28.
Reversing
Change-over selector
Fig. 29.
Change-over selector,
coarse/ne
Fig. 30.
Change-over selector for plus/minus switching (type R)
The change-over selector extends the regulating range to
twice the voltage of the tapped winding, by connecting the
main winding to different ends of the regulating winding,
and thereby reversing the magnetic flux generated by the
regulating winding. See Fig.29.
Change-over selector for coarse/fine switching (type D)
In type D switching the change-over selector extends the
regulating range to twice the voltage of the tapped winding,
by connecting or disconnecting the coarse regulating winding.
Fig. 30.