From Protection Device to Smart Grid Asset: The Evolution of Reclosers

When discussing the modernisation of power distribution networks, much attention is given to digitalisation, automation, and smart grids. However, one technology has been quietly improving reliability for decades: the recloser.

The history of reclosers dates to the mid-20th century, when utilities needed a more effective way to manage temporary faults caused by lightning strikes, vegetation contact, or other transient events. Before their widespread adoption, these disturbances often resulted in prolonged outages and manual intervention.

Reclosers fundamentally changed this approach. Early reclosers relied on oil-insulated interruption and mechanical or hydraulic controls, providing basic automatic restoration following transient faults. Later generations introduced electronic controls, improving protection accuracy and operational flexibility. Despite these technological advances, the core principle remains unchanged: automatically detecting a fault, interrupting the circuit, and restoring service after a predefined interval. This capability has significantly improved network reliability and reduced customer interruptions.

For more than two decades, NOJA Power has been part of this evolution, developing recloser technology that supports utilities in improving reliability, automating network operations, and integrating renewable energy resources. Consistent with the company's long-standing commitment to sustainability, NOJA Power reclosers are designed without the use of SF₆ gas, helping utilities reduce environmental impact while modernising their networks. As distribution networks continue to evolve, reclosers remain a key enabling technology for a smarter and more resilient grid.

Today, reclosers have evolved far beyond their original protection function. Equipped with advanced controls, communications capabilities, and integration with SCADA and Distribution Management Systems (DMS), they play a critical role in modern distribution networks by:

• Improving reliability indices such as SAIDI and SAIFI (Read more)
• Reducing outage duration and the number of affected customers
• Enabling fault isolation and service restoration
• Supporting remote operation and network automation
• Facilitating the integration of distributed energy resources (DERs) and renewable generation (Read more)
• Contributing to the development of smarter, more resilient grids (Read more)

Drawing on decades of experience in the design and application of recloser technology, NOJA Power has played an active role in supporting the evolution of modern distribution networks. Today, NOJA Power reclosers are deployed across utility networks worldwide, helping operators improve reliability, accelerate automation, enhance network resilience, and support the growing integration of renewable energy resources into the grid.

Sometimes, the future of the grid is built not only on new innovations, but also on the continuous evolution of technologies that have demonstrated their value for generations.

For more information about NOJA Power's recloser, visit www.nojapower.com.au.