Optimise your health with good lighting

The link between light and human health is embedded in our molecular make-up. Lighting levels determine our body clock, affecting the biochemical, physiological and behavioural processes that keep us alive and healthy. Light also affects our circadian rhythm, helping us distinguish between night and day and different seasons. And while light has an effect on our sleeping patterns, it also affects the functioning of our immune system and psychological well-being… (more)

Lighting and the visual system

This article is an extract from Brian Rowell’s new book, “Lighting Design and Application – a practical guide for lighting practitioners”, published by EE Publishers. It can be ordered on-line at www.eepublishers.co.za/view.php?sid=943. Lighting design is specifically aimed at providing a visual environment for optimum performance of a visual task. These tasks are almost infinitely variable, from foundries and heavy industry, schools, factories, paper based tasks, computer screens, precision assembly, hospital operating theatres, to name just some of them… (more)

Online monitoring of drives

Customers expect products to function reliably, but ensuring that they do so under all conditions is anything but a trivial matter. Consider, for example, the gear train assemblies in wind parks and in large-scale drives in cement mills. In the case of wind parks, insurance companies insist on online monitoring, particularly if these facilities are in hard-to-reach areas such as the North Sea. In such cases, an electronic condition monitoring system is indicated… (more)

Stadia – Coliseums of the 21st Century

This article describes the cutting edge information and communication technologies (ICT) installation at the Greenpoint Stadium (GPS) in Cape Town and the Nelson Mandela Bay Multi Purpose Stadium (NMB-MPS) in Port Elizabeth, South Africa.  Both stadiums are designed to host the Soccer World Cup in 2010… (more)

Principles, testing methods and applications: earth ground resistance

Why ground? Poor grounding not only contributes to unnecessary downtime, but a lack of good grounding is also dangerous and increases the risk of equipment failure. Without an effective grounding system, we could be exposed to the risk of electric shock, not to mention instrumentation errors, harmonic distortion issues, power factor problems… (more)

Testing of single phase supply connections only – Part 3

Testing of polarity in single-phase circuits – The instrument used for polarity: Insulation tester on the ohm scale, or use lowest resistance range of a multi meter. Please note: Tests to be performed with power switch off. This test determines whether the single-phase installation is correctly wired… (more)

Electrical contractors, seen from a woman’s perspective

As a woman and having seen quite a few contractors at work over our 20 years in business, I have a few points for contractors to ponder.
•Write the customer’s details down in a safe place – get names, addresses, emails, phone numbers correct and correctly spelt.   It saves you lots of frustration later.
• Where possible, make appointments and KEEP them. There is no such thing as someone being “just a housewife” with nothing to do but wait for you to rock up. It is an insult to most women who, these days, lead very busy lives. Should you run late or not be able to make it, have the courtesy to phone and say so. The customer may still not be happy, but far happier than when you just don’t pitch… (more)

Risk assessment in explosion prevention

The area classification for hazardous locations takes into consideration the probability of occurrence of an explosive atmosphere due to the presence of dust, fibres, gas, vapour or mist. It however does not consider the magnitude of damage to equipment, personnel and the environment i.e. consequences… (more)

Disposal of fluorescent lamps

I recently attended a meeting of IESSA, the Illumination Engineering Society of SA, on the safe disposal of hazardous waste – namely all mercury-filled lamps. It would seem that very little is known or being done about this major problem.  One of the members of the audience mentioned that her company imported approximately 100 000 fluorescent lamps each month.  This was one company.  It is mind-blowing to imagine how many lamps are being dumped (broken) anywhere and everywhere and how much mercury is being leeched into the environment… (more)

Intelligent Building Automation: IBA 2009 – a pity if you missed it!

I can only say to those who missed the event– it is a pity! You missed two days of riveting presentations and discussions on aspects of building automation that will shape the future of South Africa’s quest to harness energy and to use it wisely and economically… (more)

The Westcor project – a question of equity?

Following recent (apparently contradictory) media reports on the current status and future prospects of the Westcor Project to bring power from the Congo River in the DRC to South Africa, this article considers factors that may be inhibiting progress, and examines why the Westcor dream may be unachievable in its current format… (more)

The map scandal and the Methuen Map

In spite of the fact that the British had been involved in southern Africa for the best part of the century, there was an acute shortage of maps available of the two Boer republics and even of their own British colonies. In Britain, this map shortage was regarded as one of the biggest military scandals of the war… (more)

Surveying on a major airstrip upgrade

The rehabilitation of this airstrip has included the construction of  23 000 cubic metres of raft foundations, the largest ever done in South Africa, in order to provide sufficient support for aircraft landing in the dolomite risk area in which the airstrip is located… (more)

Back to basics for education

At the time of writing, a public debate is raging over the revelations contained in a draft Higher Education South Africa (HESA) report of the pilot assessments done of a large sample of students already accepted for tertiary education. The National Benchmark Tests Pilot Project, commissioned in 2005, had its first trials in February this year and included 13 000 students representing the gender and demographic ratios present in South Africa using internationally accredited procedures… (more)