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  • VIEWS & OPINION: more >>

  • LIGHTING: more >>

    • The benefits of human-centric lighting

      by Phil Hammond, Blair, Hammond and Associates

      Human-centric lighting adjusts people’s daily rhythms and improves their biological and emotional health, motivation and productivity. In 2010, a South African lighting company warned retailers not to use LED lighting as it could cause blindness. It also circulated a French Agency for Food, Environmental and Occupational Health and Safety (ANSES) report on testing and […]

    • Compliant waste management for lighting, fittings and electronic components

      by Patrica Schröder, Reclite SA

      Millions of waste lamps, fittings and electronic components containing toxins and heavy metals are discarded to landfill every year, posing threats to the environment and human health. South Africa is replacing less energy-efficient lamps with more energy-efficient variations in its drive to save energy. Although the energy efficiencies in lighting are improved, the toxicity […]

    • Contemporary trends in lighting design

      by Paul Pamboukian, Pamboukian Light Design

      One of the most contemporary trends in lighting is how humans relate to light. Not much has really changed in terms of lighting design over the last 25 – 30 years. The same principles have been in practice since the days of Richard Kelly, the American lighting designer, who is, today, considered one of […]

  • SWITCHGEAR & DRIVES: more >>

    • Solid insulation switchgear for space savings and safety

      by Mike Rycroft, EE Publishers

      Substations and distribution boards in both the utility and industry sector are under increasing pressure to reduce space usage and cost, while maintaining safety and integrity. Switchgear is the main space occupant, and efforts at space reduction are focused on reducing both the volume and footprint occupied. Solid insulation switchgear offers reduced space and […]

    • Health and environmental dangers of SF6-filled switchgear

      by Lisa Sattler Blackburn, Innovative Switchgear Solutions

      SF6 gas, used as a dielectric medium in circuit breakers and switchgear, has a global warming potential 24 000 times greater than CO2 and some of its by-products were used as chemical weapons in World War I. In life, in business, in the ordinary course of doing things, there is a certain level of […]

    • Direct torque control – a motor control technique for all seasons

      Information from ABB

      Using VSDs with direct torque control increases motor torque response dramatically. The performance of asynchronous AC motors in today’s applications comes from modern electronic controls such as variable-speed drives (VSDs) and accurate motor models whose sophisticated control algorithms can be executed rapidly by high-performance digital signal processors. Electric motors are often at the spearhead […]

  • MECHANICAL TECHNOLOGY: more >>

    • Driving a service tunnel

      by D Kent, 1967

      From the ICMEESA archive The troubles encountered in driving a tunnel to take electric cables under a South African Railways (SAR) embankment through bad soil, with the method adopted to overcome them. Because of the installation of a new arc furnace and casting plant, it became necessary to erect a new substation to provide […]

    • Correction of power factor on resistance welding machine loads

      by HJ Yelland

      From the ICMEESA archive Loads from resistance welding machines often cause trouble, especially where large machines not fitted with power factor correction are involved. The load taken by a resistance welding machine is invariably intermittent and it draws a large single phase current of low power factor (0,3 to 0,5 lagging). With modern “tube” […]

    • Welding in hazardous locations

      Compiled by Pieter Coetzee, Explotac

      Flying sparks and incorrect welding practices can cause premature failure of explosion protected equipment. Flying sparks due to welding and cutting are the main causes of fires and explosions in hazardous locations. The welding arc creates extreme temperatures, and may pose a significant fire and explosion hazard if safe practices are not followed (see […]

  • INSTALLATION & CONTRACTING: more >>

    • The importance of electrical diagrams

      by Dave Leigh, Matra Engineering

      Electrical diagrams are vital for any factory for the same reason that makes them mandatory for aircraft or nuclear plant operators: personnel safety. Although the importance of electrical diagrams cannot be over-emphasised, there are other reasons for using them which may not be as obvious. Safety of machinery For example, interlocks intended to protect […]

    • Troubleshooting power harmonics

      Information from Comtest

      When transformers and neutral conductors in balanced circuits overheat and circuit breakers trip for no apparent reason, the cause often lies with harmonics. Harmonics are the by-product of modern electronics. They are especially prevalent wherever there are large numbers of personal computers, adjustable speed drives and other types of equipment that draw current in […]

    • Finding the optimal installation angle of earth rods to reduce electrode resistance

      by Gavin Strelec and AC Mavhungu, Eskom Research, Testing and Development

      An investigation into the effect of varying the installation angle of the earth rod between 0° and 90° for a small substation earth grid. Earth rods connected to earth systems are used widely to reduce the resistance of earth electrodes for substations [1], as well as other applications. It appears, however, that earth rods […]

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