Proof Mining Services looking after mining safety with its flameproof products

Mining is an inherently harsh environment. Applications expose the wire, cable, the connectors, plugs and accessories to serious abuse, which is a common cause of failure. Choosing a high-performance industrial cable, assembly or accessory is critical to maintaining safety, and reducing labour, material and downtime costs.

The Mine Health and Safety Inspectorate (MHSI) strives towards a safe and healthy South African mining industry. The MHSI was established in terms of the Mine Health and Safety Act, 1996 (Act No. 29 of 1996), as amended. The aim is to execute the constitutional mandate of the Department of Mineral Resources to protect and safeguard the health and safety of mine employees and communities affected by mining operations.

The MHSI enforces compliance and inspectors routinely visit mine sites to identify and eliminate violations. In many cases, repairs of electrical cable will not meet standards and so replacement is often the better option, which can be a frequent and costly endeavour if a company is in the habit of using commodity cable in harsh applications. Choosing an industrial-grade cable, assembly, or accessory can reduce the overall cost of ownership while diminishing the opportunity for citations and supporting safety initiatives.

Proof Mining Services was established in 1978, initially servicing the underground connector market in South Africa, with medium-voltage connectors. By 1988 Proof Mining Services had established itself as a market leader in HT (high-voltage) cable connectors. In 1995 Proof Mining Services expanded its range to also include the low voltage plugs and sockets for underground applications

Sand mixing and compacting in the foundry

Mining cables, assemblies and accessories are utilised in various types of mining applications and intended for long-term performance in the extremely harsh environment, while providing the greatest levels of safety and productivity. The cables, assemblies and accessories can offer excellent flexibility, torsion and drag resistance, in addition to exceptional electrical, temperature parameters, abrasion and flame resistance.

In the realm of industrial operations, such as mining, where explosive atmospheres pose a constant challenge, the choice of electrical cable, assemblies and accessories becomes paramount. Hazardous area plugs and sockets, meticulously engineered to meet stringent safety standards, are your key to unlocking safety and efficiency in these high-risk environments.

Manufacturer of flameproof and explosion proof products
Proof Mining Services specialises in the design and manufacture of innovative flameproof, explosion proof and non-flameproof plugs, sockets, adaptors and cable couplers for the mining and tunnelling industries. The range includes 0.6kV through to 35kV, 120A through 800A couplers in a variation of configurations i.e. plugs, sockets, adaptors, as well as a PLM aluminium range that meets international specifications for hazardous and non-hazardous areas.

Proof Mining Services manufactures aluminium castings for its own products

Cores are hand made

Proof Mining Services can also lay claim to being the first company to offer and manufacture a complete phase segregated range of couplers within the 1.1kV, 6.6kV, 12kV and 22kV ranges. The company now also offers a full range of Exd cable glands. Exd cable glands are flameproof, which means they should contain an explosion.

Proof Mining Services was established in 1978, initially servicing the underground connector market in South Africa, with medium-voltage connectors. By 1988 Proof Mining Services had established itself as a market leader in HT (high-voltage) cable connectors. In 1995 Proof Mining Services expanded its range to also include the low voltage plugs and sockets for underground applications.

In 1998 Proof Mining Services introduced its phase segregated technology into the majority of its product lines and in 2002 Proof Mining Services expanded its range of connectors to include the opencast type PLM plugs and sockets. Today Proof Mining Services has a product range from 1.1kV 120A through to 35kV 400A, covering both underground and opencast applications.

Inside the foundry

Moulds being coated

In 2012 JSE listed Hudaco Industries purchased Proof Mining Services and incorporated the company into the Powermite stable, an existing Hudaco Industries company, as a result of the synergies that existed between Powermite’s mining cable products and the Proof Mining Services’ cable connectors. This association enabled the two companies to provide an end-to-end cable and connector solution for mining and industrial applications.

However, Proof Mining Services still operates under the banner of the GDE Group of companies. The group includes Golden Drive Engineering (a company that offers high precision turned parts, technical components, custom mechanical assemblies), GDE Services (a manufacturer of couplers and plugs for high voltage implements, primarily serving the mining industry), Kgeta Optimum Solutions (a machine shop delivering CNC milled and turned components), Proof Mining Services and Impact Pneumatics (a company that specialises in the sales, service, for-hire and repairs of rotary vane, screw and piston type compressors).

The synergy between the companies and the different products and services that they offer allows them to manufacture a large portion of the various components that make up the end product inhouse – from casting to machining to assembly.

The foundry
Proof Mining Services operates out of a 4 000 m² facility in Benoni, Gauteng, which includes its own foundry. The foundry operates four 180kg gas fired furnaces that melt brass, zinc and aluminium materials to manufacture all the castings used in the products that are marketed.

Proof Mining Services melts aluminium, zinc and copper

More castings made by Proof Mining Services

Proof Mining Services currently make use of the sand cast method to produce their castings, which includes making sand moulds and hand-made cores for each product. Inside the foundry is a custom-made reclamation plant that was manufactured inhouse.

Besides floor moulding the company also has a gravity die-casting section for certain components and have also recently started to produce certain items using high-pressure die-casting.

The foundry has its own pressure testing facility in order to test the castings to verify their integrity, employs very strict quality controls within the operation that includes visual checking of moulds and cores and temperature control of the furnaces.

The foundry is currently melting one and a half tons of aluminium, one ton of zinc and one ton of brass every month but this can vary depending on demand. The foundry currently employs around 25 staff members out of a total 80 staff across the GDE Group.

Aluminium is one of the materials most used worldwide for the construction of explosion-proof enclosures. The excellent features of corrosion resistance make this material universally recognised as the most valuable and versatile for most applications.

In respect to cast iron, aluminium has the advantage of being much lighter and, thus, facilitates both the assembly and the maintenance of the system. Furthermore, it has an excellent corrosion resistance without the need to be protected on the surface, as happens with the cast iron, which must be galvanised or varnish protected. In comparison to the stainless steels, it has a lower cost.

A connector being assembled

The final product in the assembly department

The mechanical properties of aluminium alloy castings are highly satisfactory for use in the field of flameproof explosion proof electrical components, assemblies and products.

Machine shop
The company has its own machine shop (Kgeta Optimum Solutions) on site, which machines all the castings as well as the connecting pins and insulators used within the products. The CNC equipment includes lathes, vertical and horizontal machining centers.

The company also makes use of CAD/CAM software to design and machine the over 300 components produced in the foundry and machine shop.

The fully certified test facility equipment includes a high-voltage tester, a temperature rise tester, earth scraper tester as well as testers to determine both the insertion and excursion force of the electrical contacts.

Proof Mining Services products meet all necessary local specifications such as SANS and the company also has SIRA approval on several of its ranges. In addition, ATEX approval has been granted on its 3.3kV and 6.6kV ranges and they are currently working through the entire product range. Furthermore, Proof Mining Services is ISO 9001 accredited through BVQI, since 2000.

For further details contact Proof Mining Services on TEL: 011 425 4361 or visit https://www.proofeng.co.za/