Turning Reclosers into Intelligent Monitoring Platforms

For decades, reclosers have been deployed primarily as protection devices, helping utilities identify faults, isolate damaged sections of the network and restore service reliability.

Today, the grid is becoming more complex. The increasing penetration of renewable generation, growing power quality expectations and the need for enhanced asset visibility are driving utilities and large energy users to rethink the role of field-deployed equipment.

Recognising this evolution, NOJA Power has continued to advance the capabilities of its recloser platform. What was once viewed solely as a protection device is now capable of operating as an intelligent monitoring platform, delivering reliable and actionable operational insights to support better network visibility and decision-making.

Unlocking Intelligence from Existing NOJA Power Assets

A recent enquiry from an industrial customer highlighted a challenge faced by many network operators today.

The site was supplied by a 6.5 km, 11 kV feeder and included large transformer loads alongside a 1.5 MVA solar installation. The customer's initial strategy was to deploy a dedicated Class A power quality analyser, together with the communications and software infrastructure required to collect, manage and analyse the data.

However, a review by NOJA Power engineers identified an alternative solution. Combining advanced protection, automation, communications and extensive power quality monitoring capabilities, the RC-20 has been suggested as an alternative solution for continuous visibility into network conditions instead of a separate monitoring platform.

To validate this approach, the utility recommended installing a pole-mounted OSM Recloser equipped with an RC-20 controller in series with a Class A Power Quality (PQ) Meter, enabling a side-by-side comparison of their monitoring performance under real operating conditions.

Rather than deploying additional monitoring devices, operators can often leverage existing field infrastructure to unlock valuable network intelligence and transform protection assets into intelligent monitoring platforms.

Proven Monitoring Capability

Accurate monitoring is critical to building confidence in any power quality solution. Testing has demonstrated the RC-20's capability to monitor voltage harmonics up to the 63rd order while maintaining high measurement accuracy for practical network applications. Field evaluation results showed excellent correlation between the RC-20 and a Class A power quality analyser, with the average difference in voltage measurements below 0.2% and the average current measurement difference less than 0.4 A.

Comparisons across voltage, current, frequency and harmonic measurements demonstrated strong agreement between the two platforms. While higher maximum measurement deviations were observed during rapid network changes, these differences are primarily attributable to the different reporting and averaging methodologies employed by the devices. The RC-20 synchrophasor engine reports averaged measurements every 20 ms using a one-cycle averaging window, whereas the Class A power quality analyser reports values every 3 to 4 seconds using a significantly larger averaging window.

As a result, the RC-20 is able to capture voltage and current transients with greater resolution, while the power quality analyser presents a more smoothed representation of the same events. During sudden voltage or current variations, the analyser's longer averaging period reduces the magnitude of reported peaks and dips compared with the RC-20 synchrophasor measurements. Analysis of voltage trends confirmed that measurement differences were concentrated around these transient events, while steady-state operating conditions showed very close agreement between the two systems.

The results provide further confidence in the RC-20 platform for power quality monitoring applications, with performance aligned to AS/NZS 61000.4.7 Class II requirements. By combining protection, automation, communications and advanced monitoring capabilities within a single platform, the RC-20 enables utilities and asset owners to achieve meaningful visibility into network performance without deploying a separate monitoring ecosystem.

From Protection Asset to Intelligent Grid Sensor

As utilities seek greater value from existing infrastructure, the modern recloser is evolving beyond its traditional protection role. By combining protection, automation and monitoring capabilities within a single platform, reclosers are becoming an increasingly valuable source of operational intelligence for utilities and large energy users alike.

“As the grid continues to evolve, visibility becomes just as important as protection. Modern field assets must do more than respond to faults. They need to help operators understand the conditions affecting network performance every day. This is where intelligent monitoring capabilities can deliver significant value,” says Neil O'Sullivan, Group Managing Director of NOJA Power.