The mining industry’s increased adoption of the latest IEC/SANS 61439 series of safety and performance regulations for low-voltage (LV) and medium-voltage (MV) power assemblies has encouraged manufacturers to revise the certification of their electrical products, states power management company Eaton.
The 61439 series of standards covers protection against electric shocks, the integrity of the protective circuit in electrical assemblies, the effective continuity between the exposed conductive parts of the assembly and the protective circuit, as well as the effectiveness of the assembly for external faults.
“The mining sector is proactive in adopting newer, potentially safer standards [in electrical applications], which effectively assists mining employees with safety and . . . in ensuring the longevity of the business,” Eaton mining head Trevor Sansom tells Mining Weekly.
He adds that there is a high-level focus on health and safety in the mining sector. “This is evident in the stringent and detailed technical specifications of equipment required that are stated in mining-equipment-supplier tender processes, and the rigorous health and safety rules implemented at mine sites [as dictated by] the Mine Health and Safety Act, which has contributed to the industry’s decreasing injury and fatality record over the past ten years.”
He states that manufacturers who are noncompliant with the 61439 standards will find it more difficult to provide products or solutions, based on that standard requirement, to the mining industry.
In light of this, Eaton will introduce its new IEC-type-tested assembly – the “Cx” LV power assembly that covers applications up to 5 500 A – into the South African market before the end of this year. These power assemblies are used in power distribution systems and in motor control centres, also known as MCCs, at mine sites.
“The product design is third-party-certified in accordance with IEC 61439-2 (verification by testing), and designed and tested according to IEC/TR 61641 criteria 1-7,” Sansom highlights, adding that the CX power assemblies have been servicing global markets since 2004.
Eaton introduced this product with a fully withdrawable chassis, which enables operators to remove a chassis under live working conditions while ensuring operator safety and reducing production downtime, in 2011.
“All operators are subjected to the hazards of switching and controlling electricity above ground and below ground, which makes the safety aspect of the LV and MV assemblies critical for applications, also in the mining industry,” Sansom emphasises.
Sansom highlights the success of Eaton’s Xiria E extensible ring main unit, which is used as MV switchgear in connecting or breaking a ring of transformers in electrical applications such as in mini-substations.
The product is an extension of Eaton’s Xiria block-type ring main unit, which has had extensive success in servicing the South African market since 2008, Sansom says. It includes a combination of vacuum and cast-encapsulated resin technology to provide maintenance-free MV switchgear.
Other features include, but are not limited to, safe use, as there is visible isolation through inspection windows in the front, while logical mechanical and electrical interlocks prevent malfunctioning. Primary parts and mechanisms are also in a sealed-for-life, fully enclosed housing, Sansom adds.
Eaton’s Xiria range of ring main units, FMX and UX range of primary switchgear do not contain sulphur hexafluoride (also known as SF6) – an inorganic, colourless, odourless, non-flammable and extremely potent greenhouse gas. Toxic decay products are formed when SF6 gas is subjected to an electric arc, which makes it critical for employees that are working with the faulted SF6 arced products to adhere to the strict safety equipment, clothing and waste disposal requirements, Sansom points out.
The Xiria E was launched in Europe in August 2012, but was available in South Africa only in the first quarter of 2014.
Sansom concludes that Eaton is committed to helping customers effectively manage electrical, hydraulic and mechanical power more efficiently, safely and sustainably, stressing that industry “requires bespoke safety solutions to avoid loss of life, injuries and safety stoppages”.