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  • VIEWS & OPINION: more >>

  • LIGHTING: more >>

    • Lighting emergency gear – what waveform should we use?

      by Pete Pomeroy and Stirling Marais, Cosine Developments

      This article explains the pitfalls in providing DC or a modified sinewave to drive LEDs in emergency mode. Many LED luminaires have built-in drivers, so emergency gear must either simulate mains or attempt to drive the LED with DC power. Lower-power LEDs with low power factors are easiest to drive due to their simple circuitry. […]

    • Public lighting: Lighting the way to smart city development

      by Bjorn Smidt-Hart, SMEC South Africa

      Public lighting is one of the services most visually seen by the general public within a city (though it almost goes unnoticed). Lighting provides a sense of visual safety and security. This improved sense of safety and security will often lead to an increase and further promotion of community activities, events, sport, trade, industry and […]

    • Considerations for lighting in manufacturing

      Information from Turck Banner

      Thomas Edison’s filament technology is still used for industrial applications, but there are now other options in the world of industrial lighting. The most important development for industrial lighting to date is the development of light emitting diode (LED) technology. A form of solid-state lighting, LED technology had very limited applications when it first appeared […]

  • SWITCHGEAR & DRIVES: more >>

    • The advantages of controlling synchronous motors with variable-speed drives

      by Heinz Lendenmann, Reza Rajabi Moghaddam, Ari Tammi and Lars-Erik Thand, ABB

      Synchronous motors controlled by variable-speed drives are bringing higher efficiencies to industrial applications. Most applications have a need for efficiency and for the longest possible lifetime while not increasing maintenance demands or failures. ABB’s synchronous reluctance motors are physically smaller in size, helping machine builders design smaller, lighter, and more efficient equipment. The possibility of […]

    • Earth leakage in variable speed drives

      by Colin Hargis, Control Techniques

      AC VSDs generate earth leakage currents which can cause nuisance tripping of RCDs, earth leakage breakers and others. Simple electrical devices such as motors and heaters have no connection between the AC power circuit and the earth (PE) connection. The earth connection is there to keep the device safe in the event of a short […]

    • Electrical current signature analysis for fault detection in large motors

      by Mike Rycroft, EE Publishers

      Large electric motors form the core of many industries. As machines are designed to tighter tolerances, there is a growing need, for the sake of reliability, to monitor their behaviour and performance. Electrical signature analysis is proving valuable on wide range of motors to detect both mechanical and electrical faults. Vibration analysis (VA) as means […]

  • MECHANICAL TECHNOLOGY: more >>

    • The impact of carbon tax on boiler energy efficiency

      by Grant Renecle, Combustion Technology

      Energy efficiency has become a distinguishing factor when selecting boiler for an industrial application. Considering that manufacturers are only required to prove that their products conform to the maximum continuous rating (MCR), it begs the question, how many actually offer efficiency? While the environmental discussion has had a slower offtake in Africa than in the […]

    • Preservation of cold rolled sheet by means of temporary protectives

      by DR Alan Wainwright Lake, Chemserve Oleochemicals, 1975

      From the ICMEESA Archive Problems encountered and the factors involved in the development of a successful protective formulation. The protective formulation is particularly important when shipment is over long distances and the steel is held in stock for extended periods, often under unsatisfactory conditions. This article discusses the problems encountered and the physical, chemical and […]

    • The measurement of noise

      by RPS Horn, 1974

      From the ICMEESA Archive This article is concerned with the work situation, with reference to factory noise. Fig. 1 shows some of the interrelations between engineers and factory management on the one hand and many of the other auxiliary activities on the other. When discussing noise, we deal with sound pressure magnitudes ranging from the […]

  • INSTALLATION & CONTRACTING: more >>

    • Basic electrical installation testing

      Information from Comtest

      Concern for public safety and the increasing complexity of fixed electrical installations place extra responsibility on electrical test engineers. It is therefore important to have suitable test tools for carrying out the stringent tests imposed by the International Electrotechnical Commission (IEC) and the European Committee for Electrotechnical Standardisation (CENELEC). IEC 60364 and its various associated […]

    • The importance of surge protection in the lightning protection arena

      by Ivan Grobbelaar, DEHN Africa

      To understand the need for surge protection, it is important to understand how lightning causes damage. The sources of lightning damage are quite different, and we use different types of mitigation technique and equipment to protect different items. There are two areas of concern when evaluating a building or structure, namely the structure itself, and […]

    • Understanding the basics of power measurement theory

      Information from Fluke

      Electrical power applications are changing rapidly which means the load on the electric network is changing: more harmonics and more risk of unbalance. This so-called “bad” power costs money and wastes energy. This article provides some basic theory to understand what is happening with today’s electrical applications. Apparent power To understand the relation between active […]