JOHANNESBURG (miningweekly.com) – Siemens South Africa (SA) is targeting international markets with its fourth-generation 11 MW fully automated direct current (DC) containerised trolley assist substation – the Siemens E House.

One of the six inaugural in-house-developed units heading to an undisclosed Namibia-based opencast mine was unveiled on Friday at Siemens’ headquarters, in Randburg.

Some 90% of the components of the mobile substation, used to power a fleet of Komatsu 960E trucks with a load capacity of 214 m² or 327 t, are entirely manufactured by Siemens, including the control panels, rectifier, DC switchgear and alternate current (AC) switchgear.

This was up from the historical 30% of components used, as part of Siemens’ effort to target international markets in compliance with the specifications and standards of more mature economies, such as Europe, said Siemens SA lead engineer Karl van Rensburg.

Speaking to Engineering News Online at the launch, he explained that Siemens had taken advantage of the opportunity to develop its third-generation unit when the company was awarded the bid to provide electric power to adapted diesel-electric haulage trucks at the Namibian mine earlier this year.

“There is a demand [for such substations] internationally,” he said, adding that Siemens was seeing interest from companies in Botswana and the Democratic Republic of Congo (DRC), as well as Denmark and Sweden, where Siemens was currently bidding. Van Rensburg noted that, if Siemens was awarded the Swedish contract, it would mark the substation’s entry into the European market.

Meanwhile, Siemens said that the predecessors of the new Siemens E House substation – which are 10 MW and below – are currently operating at mines in South Africa, Namibia, the DRC, Zambia and North America, and have led to quicker turnaround times, reduced maintenance and engine overhaul downtime, and higher productivity for mining operations.

Siemens SA country business unit lead for rail electrification Joey Govindasamy noted that, with the success of the technology to date in the mining sector, Siemens was also targeting clients in the rail sector.

Each 11 MW fourth generation unit has 1.8 kV DC voltage and up to 10 000 A, with the capacity to operate two 300 t trucks continuously, three trucks simultaneously for ten minutes or four trucks for one minute along the overhead power lines.

This reduces the diesel costs of ore truck haulage, which can account for up to 80% of total diesel consumption when moving uphill on ramps, by between 30% and 50%, depending on the mine’s gradient, Van Rensburg pointed out.

The substations, which are assembled in Pretoria with components imported from Germany, are housed in a 6 m x 3.3 m x 3 m container and weighs around 8.5 t when fully equipped with the 1.8 kV DC switchgear, rectifiers, 33 kV ring main unit, Siprotec AC protection device and Sitrase Pro DC Feeder protection device.

The substation also boasts PLC control, Profinet interface and HMI touch panels.

Siemens has delivered two units to the Namibian mine in the past two weeks, with the third unit, which was on show on Friday, set to be transferred within a week. The final three completed substations will follow suit in the next couple of months.