
8
Technical guide VUC
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1ZSC000562-AAX en, Rev. 1
Diverter switches
The diverter switches with vacuum interrupters are of the
high-speed, spring-operated type with resistors as transition
impedance. They are equipped with plug-in contacts that
automatically connect to the bushings in the diverter switch
housing when the switch is lowered into the housing. Guiding
facilities keep the diverter switch in the correct position when
lowering it into the housing. Mechanical coupling to the drive
is easily established by making three operations in the same
direction.
The design and dimensioning of the diverter switches offer
high reliability and long life with a minimum of maintenance
and easy inspection.
A diverter switches with vacuum interrupters combine all the
advantages of the conventional type with improved breaking
capacity, increased contact life and reduced maintenance.
The switch works according to the pennant cycle, which
gives the lowest complexity and allows full power flow in both
directions. A mechanical rectifier ensures operation in only the
direction that gives the lowest breaking stresses and contact
wear, independently of RAISE or LOWER command.
The load is commutated from one tap to the other with the
aid of the vacuum interrupters and auxiliary contacts. The
auxiliary contacts are also able to break the load current in the
unlikely event that a vacuum interrupter failure should occur.
For VUCG in service position, the load current is transferred
through the auxiliary contacts and the vacuum interrupters. All
current carrying contacts are made of low resistance material.
For VUCL in service position, the load current is transferred
through a bypass contact.
Fig. 3. Examples of diverter switches VUCG and VUCL.
The vacuum interrupters have a very long life time but yet are
mounted for easy replacement when needed, for instance in
industrial applications when the number of operations might
be extremely high.
The contact system is operated by a compact mechanical
system with integrated driving springs, mechanical rectifier,
robust mechanical system for vacuum interrupter actuating
and geneva gears for operating the auxiliary contacts and the
by-pass contact (VUCL).
All manufactured UCG.N/B and UCL.N/B, and most of the
UCG.E/T ≤800 A and UCL.E/T ≤1300 A diverter switches can
be easily replaced by the vacuum diverter switch and gain
benefit from the improvements made on this type. The VUCG
diverter switch fits all UCG tap-changers as manufactured
1977 and later without modification, which enables all UCG
tap-changers to be easily upgraded to vacuum technology.
The VUCL diverter switch fits all UCL housings manufactured
1985 and later without modification.