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Retrofittable: the VACUTAP® VM® diverter switch insert

VACUTAP® technology combines maximum reliability and minimum maintenance requirements. In figures, that means 300,000 tap-change operations without any maintenance. The diverter switch insert has a lifetime of 1.2 million tap-change operations. You can start enjoying these benefits right away by simply replacing an OILTAP® M with the new VACUTAP® VM®.

It’s never been easier to convert to our tried-and-tested vacuum technology. The VACUTAP® VM® is fully retrofittable and 100% connection-compatible with the OILTAP® M, of which there are over 70,000 in existence. All you have to do is dismantle the old diverter switch and fit the new VM® model. The same applies to most tap changers based on earlier licenses and non-authorized competitor models that are similar to the OILTAP® M and require a reliable replacement.


Interrupter Exchange Module


Preassembled Interrupter Exchange Module

For quick and easy replacement of vacuum interrupters in applications with high numbers of tap-change operations (e.g. electric arc furnaces, electrolysis, phase shifters or HVDC), we supply a fully preassembled and preset Interrupter Exchange Module with carrier unit. This has the effect of increasing transformer availability while shortening stops in production for maintenance.

While a VACUTAP® on-load tap-changer rarely requires maintenance in grid operation throughout the lifetime of the transformer, a different situation may apply in heavy-duty applications such as furnaces. In applications like these it is not unusual to have 200,000 tap-change operations per year. Every time an on-load tap-changer has to be shut down it means a temporary halt in production, which results in a financial loss for the furnace operator. To make on-load tap-changer maintenance even easier we provide service engineers with a fully assembled and preset module to replace the vacuum interrupters after 600,000 tap-change operations. This Interrupter Exchange Module ensures that the transformer is rapidly made available again while the on-load tap-changer maintains optimum functionality and reliability. ​


VACUTAP® Arc-Control System®

NEW: VACUTAP® Arc-Control System®

The unique VACUTAP® Arc-Control System® in the new VACUTAP® VM® prevents damage to the tap-changer and transformer. The perfect combination of our Advanced Interrupter Technology and patented new Dual Energy Accumulator allows the VACUTAP® VM® to guarantee reliable arc extinguishing.

Installing quality individual components is not enough to guarantee maximum mechanical and electrical reliability and durability of on-load tap-changers. That’s why we developed a system in which the Advanced Interrupter Technology, Dual Energy Accumulator and complete tap-change process are designed to work smoothly together. 

The challenge: The power fed into the tap-changer by the energy accumulator must be sufficient to ensure normal functioning at oil temperatures of minus 25°C and over 100°C. At the same time the power must be sufficiently low to minimize the mechanical loads on individual components. The electric tap-change process must also be optimally timed to ensure that the arc is extinguished even in the most unfavorable grid conditions. 

In the VACUTAP® VM® arc extinguishing is guaranteed by a combination of the patented additional energy accumulator and the Advanced Interrupter Technology developed specially for the VACUTAP® VM®. The kinetic energy output suddenly by the main spring accumulator is stored in the additional spring and transferred with a time delay to the diverter switch insert. This allows the opening and closing speeds of the vacuum interrupters and auxiliary switches to be selectively controlled, ensuring reliable arc extinguishing under all conditions. 

Advanced Interrupter Technology

We are the only provider in the world that has been collaborating with a brand-name manufacturer for over 20 years to develop all our vacuum interrupters for use in tap-changers. The expertise acquired from this experience was plowed into the design of the new Advanced Interrupter Technology for the VACUTAP® VM®. This technology provides reserves for transformer operation even under extreme conditions. We were able to demonstrate the overload switching capability of the vacuum interrupters even after 600,000 tap-change operations.

Because the tap-change chamber is hermetically sealed, with VACUTAP® technology the arc does not come into contact with the environmental medium. As a result, the insulating capacity of the diverter switch is not affected by tap-change operations and tap-change properties are not impaired by aging of the environmental medium. This technology is already established all over the world in medium-voltage circuit breakers and high-performance contactors. However, decades of experience have shown that the requirements and loads in on-load tap changers make it necessary to use specially designed vacuum interrupters. There are now over 130,000 of our interrupters providing reliable service worldwide.


VACUTAP® Step Protection System®

New: VACUTAP® Step Protection System®

The new VACUTAP® VM® features a unique system that protects the diverter switch insert against tap short circuits in the event of overvoltage on the grid (e.g. as a result of a lightning strike or switching operations): the VACUTAP® Step Protection System®.

Unlike the spark gaps normally used in this market segment, the overvoltage protection components in the VACUTAP® VM® have the advantage of less scatter in their response values. This translates into optimum insulation coordination inside the diverter switch, which in turn prevents destruction of the insulation protecting the current paths, all with different potentials, in the diverter switch as a result of overvoltage on the grid.

Other benefits at a glance

  • Maintenance interval of 300,000 tap-change operations with no time component
  • Lifetime of diverter switch insert: 1.2 million tap-change operations
  • Suitable for both grid and generator operation as well as electrical arc furnaces, HVDC, electrolysis, rectifiers and phase shifters
  • Minimal maintenance requirements yet maximum lifetime
  • Factory-built for selected alternative insulating fluids
  • Also suitable for use in earthquake zones
  • ATEX certification (for use in explosive atmospheres) applied for

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