For many small Australian businesses the availability of international imports from multinational corporations is a constant threat – specifically cables. With ever changing standards and material requirements, the strategies and technical methods used to surpass manufacturing limitations despite these constant challenges are impressive.
Recently the issue of overseas imports versus locally manufactured products and the residual effect has been a highly publicised and controversial issue. The aim of this article is not to debate, but t o explore the rapid progression of Australian manufacturing capabilities and highlight the positive effect these small Australian manufacturers continue to have within the industry.
Australia’s changing circumstances have necessitated a shift in focus for mining over the past decade. Industry standards and specifications are expanding and the use of shielding, high temp and halogen free compounds are consistently increasing. As a result, cable manufacturers are cutting their costs and boosting productivity.
Mining machines work in a harsh and unforgiving environment, both on the surface and underground. Many of these machines are mobile and their motive energy source is of ten electricity. Because of the harsh environment and special requirements for electrical distribution at mines, cables used on mining machines and to supply electricity are specially constructed.
Electrical distribution systems and cables have to be designed so that in the event of damage to a cable, the risk of electrocuting someone, causing a major fire, catastrophic failure of the cable or igniting methane gas has to be minimised.
When selecting cables and the vast range of materials used to develop a cable, apart from considering the type of application and the harsh mining environment (mining cables are particularly susceptible to damage) the electrical distribution system is an important factor. The electrical distribution system protection and method of ear thing is particularly important. If the incorrect cable is selected, the safeguards provided by the electrical protection and the earthing may be compromised. For this reason, it is important that advice is sought from a competent electrical engineer before selecting and installing a mining cable.
The electrical equipment and electrical installations within the mining industry require high standards of design, installation and maintenance. Recognised standards are not mandatory; but when followed provide a way of meeting safety and health obligations. Most notable Australian cable manufacturers are compliant with Australian/New Zealand standards resulting in protection techniques for electrical equipment and electrical installations in explosion risk zones.
There is a need for cables that are tough and that have a great deal of flexibility. Some of the features seen in underground coal mining cables are also desirable in cables used in surface mines – especially individual screening of power conductors.
Different types of cables have different constructions and different voltage ratings. A key feature of most mining cables is t he provision of earthed screens around each individual power conductor. These screens are provided so that if a cable gets damages the most likely type of fault is an earth fault. Combining the earth fault limitation and the fact that the most likely fault is going to be a raltively low energy earth fault, the likelihood of a failure of the cable or a fire is significantly reduced. When combined wit h fast acting earth fault protection the likelihood of electrocution is also significantly reduced.
The need for these cables to be tough and be used in extremely harsh conditions is testament to the capabilities and understanding of Australian manufacturers. They know better than most that research and development are vital to withstand the pressures in such an unforgiving and highly demanding market. There is a huge focus on innovation, skills and technology development and finding new market opportunities but most of all, Australian manufacturers comprehend the importance of providing safe and high quality products.
By Katie Funch Bambach Wires and Cables