NOJA Power

Technical Article

Published 02/2024

Key Components of a Single Phase Recloser Installation

NOJA Power Single Phase Recloser Installation

Switchgear engineering firm NOJA Power have a range of Australian-made single phase reclosers available for protection and control of the overhead distribution network. Spanning the medium voltage range, NOJA Power’s single phase OSM Reclosers provide reliability performance improvements, fire mitigation, and power system control.

In this article, we explore a few key considerations with NOJA Power’s Single Phase Recloser installation to guide applications of the system in the distribution field.

A Single Phase OSM Recloser in Te Kuiti, New Zealand
A Single Phase OSM Recloser in Te Kuiti, New Zealand

Choice of Controller

The NOJA Power OSM Recloser single phase product is compatible with the full suite of NOJA Power RC series Recloser Controllers. The entry level option is the RC-02, a dedicated single phase recloser derived from the standard RC-10. While the RC-02 provides the equivalent protection and control function as the standard tier RC-10, the RC-02 skips the HMI panel, downsizes the battery capacity and relies on a PC or mobile device to configure the unit in the field. These cost savings make the RC-02 the most economical option.

The mid-tier offering is the RC-10. This unit is compatible with all NOJA Power Reclosers, including the single phase devices. This unit offers extensive protection, control and monitoring capabilities, and the shared platform with three phase devices allows network operators to standardise on spare parts.

Finally, the top tier offering is the NOJA Power RC-20. This flagship device offers the highest sampling rate and data capture capability, allowing the connected OSM Recloser to act as a power quality monitor. This combination function saves significant Capex in comparison to a discrete Power Quality Monitor plus Recloser installation, where the components are sourced from different vendors.

A SCADA Integrated Single Phase NOJA Power OSM38 Recloser
A SCADA Integrated Single Phase NOJA Power OSM38 Recloser

Choice of Voltage Class

NOJA Power’s Single Phase reclosers are single pole variants of their three phase counterparts.

This means that the devices are also rated in Phase to Phase Voltages, which is an occasional source of ordering error. An OSM38 Single Phase unit is rated at 38kV phase to phase, which implies a 21.96 kV rating phase to ground. Care must be taken at installation to ensure that the designated rating matches the expected voltage on the line. This is especially important for the Auxiliary voltage supply transformer (VT), since this VT will need to provide the controller’s power supply.

NOJA Power offers single phase reclosers based on the OSM15, OSM27 and OSM38 designs, which are rated to 15, 27 and 38 kV Phase to Phase respectively.

Choice of Accessories

Common accessory choices for the NOJA Power OSM Single Phase Recloser include bird guards, auxiliary supply voltage transformer kits, or the combined mounting bracket that simplifies installation. NOJA Power recommends the use of bird guards on all installations, along with surge arrestors and insulated cable tails that offer frontline mitigation for wildlife and vegetation contact issues.

For utilities looking to automate their network, communications peripherals such as radios or cellular modems are commonly installed in the RC series control. All RC series Controllers provide a local DC power supply for communications accessories, simplifying the process of SCADA integration of the Recloser Controller.

A Single Phase OSM Recloser in Rural Queensland, Australia
A Single Phase OSM Recloser in Rural Queensland, Australia


NOJA Power has over 99,000 installations of OSM Reclosers in 106 countries worldwide. The Single Phase recloser brings reliability to Single Wire Earth Return and Single Phase lateral lines.

“Our single phase products are literally one pole versions of our three phase products and enjoy all the rugged reliability their three phase versions deliver globally,” says NOJA Power Group Managing Director Neil O'Sullivan.

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

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