Siemens launches a new Ring Main Unit (RMU) customized for South African market requirements

With a population of over 57 million, South Africa’s future growth is evidently dependent on energy consumption and distribution. The country’s current energy landscape is largely dominated by distribution failures.   

Authorities are not only planning for more structured infrastructure but also smart solutions to increase the reliability and reduce losses.

Siemens has developed a Ring Main Unit (RMU) 8DJH ST for this market considering all the important factors required. The Siemens RMU is rated up to 12kV, 630A with short circuit rating of 21kA for 3 seconds and is ideally suited for all distribution applications of rural and urban areas. The RMU can be customized to meet various ever evolving technical and functional customer specific requirements.

This solution is environment friendly, hermetically sealed and gas insulated. The RMU is type tested for Internal arc 21kA for 1 second with A FLR classification for both tank and cable compartment.

The South African Market is specifically driven by the separate cable testing facility required in these RMU’s therefore, Siemens has provided a completely interlocked and type tested, separate cable testing facility which is fulfilling all requirements as per latest SANS standard 1874. To achieve maximum operator safety, Siemens has done the internal arc test on the RMU with the door of the cable testing facility open.

8DJHST RMU is automation ready and can be provided with internal RTU’s making the system smart grid ready.

This solution makes installation and operation simple. The safety features, compact design and value for money makes this RMU suitable, not only for the utility distribution network but also for various infrastructure and industrial applications.

For further information contact:

Gert Hoffman

Tel.: +27 (10) 222 7231
Mobile: +27 (79) 529 7086


Sebastian Hlongwane
Tel.: +27 (10) 222 7444
Mobile: +27 (63) 697 5275


Mavel Moraba
Tel.: +27 (10) 222 7144
Mobile: +27 (72) 646 4886