Modern Mining October 2020

Group, Kumba Iron Ore, AngloGold Ashanti and sev- eral others. The company has also partnered major OEMs such as thyssenkrupp, Takraf and Sandvik. Mobile is the answer With mines seeking to cut their costs at every oppor- tunity, Joubert believes Hamar Controls’ mobile electric substations and control cabins offer a practi- cal solution for remote mining projects, pilot plants, time-sensitive projects and plants that may need relocation from time to time. The company offers two main types of mobile substations in the form of standard containerised and custom-built electrical substations. The con- tainer substations are built using either new or used shipping containers as a base, with several modifications made for it to be suitable for use as a substation. The wooden floors are removed, and re-enforced steel floors are installed. The roof and walls are insulated and emergency escape doors are installed together with air conditioning and lighting. Depending on customer requirements, further addi- tions such as pressurisation and fire protection can be installed. The standard containerised substations, says Joubert, come in 3 m, 6 m and 12 m sizes with a width of 2,6 m. “If the customer wants a different size to these standard ones, we can still customise to fit the specification or requirement,” he says. Out of the containerised enclosures, Hamar Controls can build control rooms, laboratories, bat- tery centres, dedicated plant or equipment rooms and electric substations. When it comes to electric substations, the company offers low and medium voltage solutions. Low voltage is up to 1 000 V, while medium voltage is anything up to 33 kV. The other type of mobile substation is custom- built units, where a customer may need a control room or electric substation that may not fit in a stan- dard container. Often this is dictated by the need for more space. “Electric equipment generates heat and you need ample space to cool the area,” explains

Joubert. “In most instances larger mobile substations are a result of either simply needing more space or there could be temperature or explosion venting constraints where you need more space to dissipate the temperature or expansion of gases, resulting from a possible switchgear explosion.” The purpose-built mobile electric houses are made out of steel with an internal subframe, outer steel sheeting and typically chromadeck inner sheeting. Insulation panels, usually fire retardant, are sandwiched between the outer and the inner sheeting. These mobile units can come virtually in any size, with the only restriction being transport. “If they become too wide, they are difficult to transport. Typically these would be in the order of around 3,5 m to 4 m wide by 8 m to 12 m long,” explains Joubert. In the line of purpose built enclosures, Hamar Controls also designs and supplies purpose built control cab- ins, mostly for use on materials handling machines. Key advantages Containerised and custom-built electrical substations offer an array of advantages over their traditional

Hamar Controls team at the Roodepoort factory with a mobile electric substation for a Mozambican mine.

Hamar Controls supplies mobile control stations for materials handling machines.

October 2020  MODERN MINING  11