Much about electronics cooling systems was simpler in the past. If greater heat production or even dangerous heat concentrations were expected, fans were first mounted. These provided cooling airflow, gave us a clear conscience, and were generally sufficient to make us feel like we were on the safe side. However, with the increase in power and packaging density of electronics, the range of sources generating heat became greater and greater to the point where it was necessary to resort to active climate control units and water cooling, directly at the processor. The correct selection and sizing of the cooling components can no longer be taken lightly as this may determine economic success and future security of the entire investment as well as the trouble-free operation of entire production systems and processes.

Take note


•Cooling industrial electronic systems is more complex than in the past.
•Cooling needs cannot be guessed, but should be carefully evaluated and simulated.
•Organisations that specialise in enclosure cooling can partner with you to provide an optimal solution.

About the author
Ralf Schneider currently holds the position of director of international product management, enclosure climate control systems at Rittal in Herborn.
Rittal can locally be contacted through Melanie Jackwerth on (011) 609 8294 or mjackwerth@rittal.co.za.

WEG, the leading international supplier of Variable Speed Drive (VSD) and motor combinations, has introduced a new and innovative VSD technology to the market that offers significant benefits to users. This article will give the reader some insight into this exciting development, and presents a technique which optimises the relationship between torque and temperature in inverter-fed induction motors for speeds below the base speed.

About the author
Johan van Niekerk has worked in the drives industry for over 20 years. He first gained practical experience as a technician involved hands-on with installations and applications. Thereafter he has filled various positions including project manager, business development manager and drives manager. Johan currently holds the position of manager at Zest Drives and Automation.
Johan can be contacted on (011) 723 6000.

Take note

•Effective motor cooling is difficult at low speeds.
•A technology has been developed that minimises total losses.
•Minimisation of losses virtually eliminates the need for derating or forced ventilation.

In soft-start devices the semiconductors have to withstand extreme temperature swings, which is why good load cycle capability is a must. With purpose-developed thyristor modules, ultra-compact soft starters that meet this demand and have a good cost-to-performance ratio, are now available.

Take note

•New purpose-developed thyristor modules provide better heat transmission resistance between semiconductor chip and heat sink due to lowerheat transmission resistances.
•Modern thyristor modules offer a very high degree of reliability thanks to use of pressure contact technology (no solder layers).
•Collaboration between drive and starter manufacturers and semiconductor specialists provide benefits to the user.

About the authors
Melanie Gill currently holds the position of product manager at Semikron Elektronik. Thomas Hund currently holds the position of product manager for soft starters at Siemens A&D.
For more information contact Evelyn Dowse at Semikron on (012) 345 6060 of evelyn.dowse@semikron.com.

We cannot escape the need for lighting. While much of the emphasis has been placed on lighting in an industrial environment, we’d like to focus in this article on a residential setting. The setting, however, is remarkable. The article will focus on the automation aspects of lighting, using a dwelling at the Shandon Wildlife Estate, near Nelspruit, as an example.

Take note

•Lighting affects your living and working environment.
•Modern buildings require central control and full automation.
•KNX/EIB open bus technology meets ISO/IEC 14543-3 requirements.

About the author
Paul Mollentze started his career at Sasol in 1980, working on 22, 11, 6,6 kV, 525 V and low voltage systems, including drives and PLCs. Thereafter he became plant production manager in a Natal-based plant and later joined a Phalaborwa-based mining company as senior purchasing electrical instrumentation projects officer. Paul joined Rockwell Automation in 1996 where he was involved in industrial networks and PLCs for eight years. After qualifying in Germany as KNX/EIB systems programmer in open building automation, Paul now holds the position of technical advisor/project manager: Building Automation Systems with BIDVest Voltex Head Office and Lighting Division.

Paul can be contacted on 082 419 1435 or paulm@voltex.co.za.

BCP Engineers jooin SSI Bytes expands school technology programme in KZN R30M plant upgrade at Alstom Power Transformers makes it world class facility Value-added training from Schneider Electric! An action-packed rally

Robust subracks for extreme conditions Industrial Design Award for Spectro Phoenix wins Toyota contract Byte's international business grows Alstom Signaling wins Khayelitsha contract Endress + Hauser acquires Pyrotemp services Altech announces solid growth Beckhoff invests in India

Over the past few months we have examined aspects of this critical topic [1,2]. Significantly, there is clear evidence that a variety of switchgear users are re-examining their maintenance procedures and focusing on ensuring the safety of their plant. This final article considers a more specific topic, that of air, oil, vacuum and SF6 technologies.

About the authors
Fernando Bolota is a PrEng, Fellow member of the SAIEE, and is a registered certificated mechanical and electrical engineer. He currently holds the position of marketing and customer service strategy manager at Alstom SA and is responsible for the Knights site. Fernando has over 25 years experience in the industry during which time he presented a number of papers and published articles on various facets of switchgear.

Fernando can be contacted on (011) 820 5140 or fernando.bolota@alstom.co.za.

Take note • Maintenance ensures the safety of personnel and plant. • Fairly standard considerations apply to all types of circuit breaker. • Different breaker technologies require specific interventions to ensure safe and reliable operation. • Expert assistance should be sought to avoid costly errors.

In this article we look very broadly at measurement. Instruments are available to measure any number of parameters. Many of these parameters are necessary to control a process, and other may need to be done as required as part of an auditing process, or as part of a maintenance programme. R
About the author
Natalie Pryor, marketing manager at unitemp, holds a Degree in Marketing Management from the Cape Peninsula University of Technology. She has been with the company for two years and is responsible for 14 industrial b2b brands across six strategic business fields, catalogue and web development, marketing team leader, business communication, exhibition and PR management.

Natalie can be contacted on (021) 762 8995 or nataliep@unitemp.com.

Take note


•To measure is to know.
•There is an instrument that will allow you to measure what you need to do.
•Certain test instruments must be available to facilitate maintenance programmes.