NOJA Power VISI-SWITCH® Installations in Hong Kong

Electrical distribution switchgear engineering firm NOJA Power confirm multiple installations of their NOJA Power VISI-SWITCH® Load Break Switch in Hong Kong.

The NOJA Power VISI-SWITCH® is the world’s first enclosed solid dielectric load break switch with integrated visible isolation. With an enclosed design, the NOJA Power VISI-SWITCH® offers improved reliability over traditional air-break switches, whilst preserving the visible isolation gap necessary for many overhead lines works practices.

With the high humidity, rainfall and coastal proximity, the Hong Kong climate provides a clear demonstration of the environmental resilience of the NOJA Power VISI-SWITCH®.

The NOJA Power VISI-SWITCH® has zero SF6 gas, instead relying on a solid dielectric insulation system. The design consists of a Vacuum Interrupter in series with an air-insulated isolator. Electrical making and breaking is accomplished by the Vacuum Interrupter, while the isolation and BIL duties are achieved by the series isolator.

This multistep operating sequence is transparent to operators. A single, conventional operating lever is provided. Pulling this lever charges an overcentering spring mechanism, and when sufficient energy is stored, the opening sequence commences automatically. The VI executes an open operation, followed by the isolators withdrawing to provide the required BIL.

When closing the switch, the same charge mechanism harvests the lever-pull energy, then when sufficient energy is stored, the isolators are closed before a VI close operation is triggered.

Unlike existing technology, the isolation break in the NOJA Power VISI-SWITCH® is clearly observable, allowing lines operators to confirm network isolation before placing earths or continuing their network maintenance.

“We are very proud of our NOJA Power VISI-SWITCH® product,” says NOJA Power Group Managing Director Neil O'Sullivan.

“ With the net carbon zero target placed upon our utility customers they are eliminating SF6 enclosed load break switches from their network. The NOJA Power VISI-SWITCH® is an ideal replacement still offering the reliability benefits of an enclosed switch but using field proven vacuum interruption combined with an in-series isolator that can be viewed in the open position through the patented gap in the bushing. So, linesmen can see the visible break and be confident they have isolated the line. ”

As the electrical distribution networks of the world work towards decarbonisation, the NOJA Power VISI-SWITCH® presents a sustainable alternative to SF6 enclosed load break switches.

For more information, visit www.nojapower.com or contact your local NOJA Power Distributor.