A migration from the obsolete COROS Supervisory Control And Data Acquisition (SCADA) to Simatic WinCC Human Machine Interface (HMI) was performed for Mittal Steel South Africa’s Saldanha plant. Two HMI systems were created: one to interface to a Programmable Logic Controller (PLC) process bus and one to a Simadyn-D process bus. The migration was performed by manually generating SCADA graphics generating tags through Automation System/Operator Station (AS/OS) compile and Systematic Project Engineering (SPE) for the respective systems. The entire project was made accessible through Simatic Manager in order to follow good engineering practice guidelines. Siemens option packages Simatic Audit, Connectivity Pack, Dat@Monitor and Logon were also engineered for the system.

Take note
•SCADA was upgraded from COROS to WinCC using good engineering practice guidelines.
•Standards were created and finalised early to minimise changes once software development had begun.
•Approval of standardised objects was essential to the success of the project.

Olflex control connector system Local company launches HMI Surge protection for Ethernet and ISDN lines Blueginger specialised charger system Cisco and Rockwell collaborate The Wago radio family Netshield expands horizons New terminal systems from Rittal Vizmine breaks ground

Since the invention of the electric motor, there have been many advances both in materials used, and in impregnation technology. This article discussed the trends in South Africa.

Take note
•An impregnant must provide good electrical and mechanical properties.
•An impregnant must penetrate into the windings fully and not degrade during curing.
•Solventless resins offer significant advantages over varnishes in many applications.


About the author
Paul Senior has a BSc (Honours) and MSc in Chemistry obtained from the University of Natal. He has vast experience in the manufacture and application of low and high voltage electrical insulation materials. Paul currently holds the position of technical sales manager, wire and insulation, at Wilec.

Power supplies with a dc input voltage of 360 to 900 V can be directly connected to the intermediate dc bus of a frequency drive. The advantages are interesting but special precautions are required when connecting the power supply. This article considers this possibility. Take note • Switching power supplies can be supplied from a dc-bus. • When ac mains fails, there is often still a supply on a dc-bus. • Dc bus voltage can be maintained by motor regenerative braking. • Modern switching power supplies are not affected by the noise on the dc-bus. About the author Bernhard Erdl is President of Puls Gmbh. Puls is locally represented by Current Automation. For more information contact Ettienne van der Westhuyzen at Current on (011) 462 4253 or ettienne@switches.co.za.

If you only have just one motor to operate then you don't need a universal drive system. However, as soon as several drives are required in a machine, a plant or a company, then it certainly pays off if all of the drive applications involved can be addressed using just one system.

Take note
•Limiting the types of equipment makes sense.
•Using a particular drive simply because you have similar one’s installed may not make sense.
•Separating the power and the intelligence of a drive provides immediate flexibility.
•If you have more than one motor to control, a universal drive system must be considered.


About the author Peter Arnold has his Dipl.Ing. His job function is currently business development for motion control systems in the Siemens Automation and Drives Group in Germany.
Siemens can be contacted locally on 011 652 2000 or via Siemens Business Services quoting the code A&D GC 544/05 at karin.kaljumae@siemens.com.

New TeSys T for South Africa! Conserving energy for wastewater treatment facilities Breakdown repair of a fan motor Eliminate motor burnout Safe, fast and reliable relays Powerful inverter from Hitachi WEG invests in increased production

Altech acquires Com Tech Spescom founder hands over reigns Honeywell acquires Enraf Five-year supply contract to Alstom Adroit attains Corporate Membership to the OPC Foundation Ana-Digi Systems and Voltex joint venture Schneider and MGe in exclusive negotiations CSense Users' Conference Inferior energy efficient light bulbs in the market E+H announces international appointment ABB helps Eskom upgrade power supply MTL acquires percentage of RTK On-line Spectro Campus Moeller wins big Tectra's repair facility Nampower to raise R3 bn for network expansion

Telecontrol, remote monitoring and automatic control of networks rank as the most pertinent solutions for improving the performance of medium voltage (MV) electrical distribution activity. They optimise both operating costs and capital expenditure. These benefits require careful and critical consideration.

Take note
•MV sales into building, infrastructure and utility sectors are rising rapidly.
•Networks are heavily loaded and often not optimally maintained.
•Digital intelligence and communications add significant value to MV networks.


About the author
Gerrit Steyn has been with Schneider Electric for more than five years and he is responsible for the Energy and Infrastructure Division in South Africa. His skills and in-depth knowledge of Schneider Electric offerings allows him to recommend solutions and not just products, by incorporating energy efficiency, metering and monitoring, MV protection, and power factor correction into his offering.
Gerrit can be contacted on (011) 254 6400 or gerrit.steyn@za.schneider-electric.com.

New spec distribution transformers gain Eskom acceptance High performance split-core current transformers Network strengthening substation contract awarded to Alstom Multi-function transformer testing WEG supplies Sisher

Power supplies with a dc input voltage of 360 to 900 V can be directly connected to the intermediate dc bus of a frequency drive. The advantages are interesting but special precautions are required when connecting the power supply. This article considers this possibility.

Take note
•Switching power supplies can be supplied from a dc-bus.
•When ac mains fails, there is often still a supply on a dc-bus.
•Dc bus voltage can be maintained by motor regenerative braking.
•Modern switching power supplies are not affected by the noise on the dc-bus.


About the author
Bernhard Erdl is President of Puls Gmbh. Puls is locally represented by Current Automation. For more information contact Ettienne van der Westhuyzen at Current on (011) 462 4253 or ettienne@switches.co.za.

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