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  • VIEWS & OPINION: more >>

  • LIGHTING: more >>

    • How to measure thermal resistance of LED emitters and arrays: Part 1

      Information from Lumileds

      The process used to determine thermal resistance values from the LED junction to case and LED junction to Ts reference point. Thermal performance is the most critical aspect of a well-designed LED lighting system. Lighting installations with proper thermal designs have higher efficacy, meaning more light can be extracted using less energy, providing better long-term […]

    • Which light metrics should you specify for your application?

      by Daniel Prozesky, LEDwise Lighting

      Correlated colour temperature and colour rendering index are becoming outdated as lighting metrics such as LED technology develops and customers become discerning. Selecting the correct LED lighting products for both exterior and interior spaces has become essential in today’s fast-growing built environment and, with the advancement of LED, it is now easier to select suitable […]

    • Surge protection for LED mast lights

      Information from DEHN Africa

      Notes on providing lightning protection for LED mast lights with double or reinforced insulation; large masts fitted with supply distributors PVC masts and others. LED mast lights for street, walkway and open space lighting are mounted at light point heights of several metres to ensure large fields of illumination. This, however, is only possible if […]

  • SWITCHGEAR & DRIVES: more >>

    • Defining short-circuit values for circuit breakers

      by Joachim Becker, ABB

      Power distribution requires distribution switchgear to protect installations but “short-circuit current” often varies. Distribution switchgear is needed to deliver electrical power safely to the end-user. Such switchgear and distribution boards must be designed to protect the installation by interrupting faulty circuits and guaranteeing continued operation for non-affected circuits. Breaker types Short-circuits place equipment under great […]

    • Electric motor performance testing and reliability assessment Part II

      by Hugh Falkner, Fred Nelson, Geoff Parry, Anibal de Almeida and João Fong, Leonardo Energy

      This article explores how the cost of condition monitoring for motors can be optimised through examination of the value of each test performed. Part I of this article (see Vector, January 2019, page 24) explores reliability-centered maintenance; the ideal frequency of condition monitoring, the management of spares, assessment of motor efficiency and the risk of […]

    • Magnetic coupling offers a smooth ride for variable speed loads

      by Mike Rycroft, EE Publishers

      Variable speed drives (VSDs) usually consist of a variable frequency source derived from the main supply by means of a DC converter. Techniques using magnetic coupling allow the motor to be run at its optimum speed while supplying a VSD to the load, as well as providing mechanical separation of motor and load. Magnetic couplings […]

  • MECHANICAL TECHNOLOGY: more >>

    • Bearing and seal design considerations for tunnel boring machines

      Information from SKF

      The safe, reliable operation of tunnel boring equipment relies on the integrity of critical bearings and seals. Once construction starts, there’s no going back. A tunnel boring machine (TBM) is not equipped with a reverse gear, so it is imperative that the machine is able to complete its job without suffering any significant mechanical failure […]

    • Sorghum cultivar sweetens prospects for biofuels

      by Mike Rycroft, EE Publishers

      Until recently, the biofuels industry in South Africa was based on maize and jatropha as feedstock. This changed when biofuels were limited to non-food and non-toxic crops.  Initial expectations for the biofuels industry in South Africa were based heavily on specific crops as feedstock but the main contenders, maize and jatropha, have been removed from […]

    • Fire resistant transformers for food processing installations

      by Engineering in Britain Information Services, 1967

      From the ICMEESA Archive In food processing applications, pyroclor-filled transformer units save space and curb the costs involved with cable installations. In a modern food factory where electric power may be required for boilers, ovens, dryers, refrigerators and furnaces, as well as for mixing, grinding, sorting and packaging machinery of all kinds, the cost of […]

  • INSTALLATION & CONTRACTING: more >>

    • Parking and charging management for electro-mobility

      by Thorsten Temme, Phoenix Contact

      The challenge behind Germany’s largest electric filling station was to integrate 50 charging points into a parking garage with specific structural conditions and to supply it with PV power. Increasingly more companies in Germany want to electrify their vehicle fleets. Bechtle, the country’s largest IT systems house, has incorporated the issue into its sustainability strategy. […]

    • Monitoring surge protection devices intelligently

      by Holger Heckler, Phoenix Contact Germany

      The options available for monitoring and inspection of surge protective devices. The status of surge protective devices is transmitted and evaluated throughout the system or between systems to able these devices to react quickly to overloads or failures. Sensitive electronic devices are increasingly being installed in areas where high system availability is required. Surge protective […]

    • Testing the acoustical noise of a generator set and interpreting the data

      by Dr Shashikant More, Cummins Power Generation

      Large generator sets produce high levels of noise that must often be mitigated to meet national regulations and directives. This usually involves key decisions about the optimal generator set location and installation, how to design noise control systems and other factors, which is why it is important to conduct accurate noise level assessments timeously, before […]