NOJA Power

Technical Article

Published 06/2024

External Load - Three Common Communications Accessories for the NOJA Power RC Series Control

NOJA Power OSM Recloser and RC-20 Controller

NOJA Power’s OSM Recloser has helped distribution network operators in 106 countries to improve their power reliability by up to 80%. Once operators have secured the benefits of reclosing, the next process improvement is to consider remote control of these assets.

While the RC-15 and RC-20 Series Recloser controls offer integrated communications capabilities, all RC series controls offer a DC supply load to power communications accessories.

In this article, we review three of the most common communications connections cohabiting the control cubicle.

The External Load Supply

Firstly, a quick review of the External Load Power Supply for Communications equipment. NOJA Power’s RC series recloser controls have a controlled, 12V DC power supply for connecting communications equipment.

This controlled supply regulates power delivered to communications accessories, but also has the ability to power cycle comms equipment if the connection fails.

For the RC-10 and RC-15, the power supply is a 20 W average on a rolling 60 second window. There is an optional high-power accessory (part code KIT-0049) for the RC-10/15 platform that brings that power average up to 40 W. This typically finds application for older high power radio systems.

The RC-20 Recloser Control provides even higher power availability, with a rolling average of 50 W for 60 seconds.

The internals of a NOJA Power RC-20 with Radio/Modem mounting plate (Communications Tray) – RHS of image.
The internals of a NOJA Power RC-20 with Radio/Modem mounting plate (Communications Tray) – RHS of image. © NOJA Power 2024

Fibre Modems

Optic fibre is commonly applied in the power systems industry. Optical fibres provide excellent electrical isolation, as communications rely on electrically non-conductive fibre leads.

However, Fibre optic networks come in a vast range of optical wavelengths, connector types, cable types and data transfer standards.

While many electrical installations often use the 100BaseFX type connections, the terminations may either be ST or LC type.

To maximise flexibility, end users can supply their own fibre modems which meet their exact networking specification. NOJA Power offers the MOD-0017 Multimode 100BaseFX with LC type connector, or MOD-0013 ST type 100BaseFX devices. These can be factory pre-fitted. Alternatively, users can add their own fibre modems and connect them to the integrated comms ports of the RC Recloser Control.

The power supply for these modems are covered under the external load, and most comfortably sit under the 20 W rolling average of the RC-10 base design.

Dual Sim Modems

Cellular communications are a common technique for remote access to reclosers. However, some regions suffer suboptimal service provision. In these cases, a dual sim modem allows operators to switch between providers should a network link fail.

MOD-0015 is the NOJA Power Dual SIM modem option, which is powered through the external load supply of the RC and fitted to the communications tray. This module provides improved network performance in areas of poor coverage, offering maximum reliability and network uptime.

Radio Communications

Radio communications offer ruggedised low bandwidth data communications for Recloser controllers. Unlike cellular comms which generally rely on a third party provider, most radio installations are fully controlled by the distribution network operator. The added range of this technology also makes it favourable for mission critical communications, as it does not rely on third party power supplies in cell towers for a communications link to be established.

Despite the lower bandwidth for data transfer, radios remain a popular option for SCADA integration with network assets.

Some high power radios require additional power to meet their peak transmission demands. While this is usually handled in an RC-20 device, the RC-10 and RC-15 units can have a boosted external load output through KIT-0049.


The external load power supply from NOJA Power’s RC series controls is a core method for communications versatility. This 12 V DC supply ranges from 20 W to 50 W average power supply, allowing the RC to host a multitude of SCADA and communications peripherals.

“Our RC range of control cubicles has been designed for communications equipment to be installed in our cubicle with space, communications ports and power supply all available integral to meet all communications requirements,” says NOJA Power Group Managing Director Neil O'Sullivan.

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

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