Profinet is an ‘all-encompassing’ Industrial Ethernet solution for automation, offering superior performance across a wide range of applications and industries. As well as delivering realtime Input/Output (IO) performance, it fully supports the sub-millisecond demands of advanced motion control. It can easily connect to other networks, in particular existing fieldbus systems and process automation networks.

About the author
Hertzog Makete is a product specialist in industrial communication specialising in both Ethernet and Fieldbus technologies such as Profibus and Profinet. He received his training in Germany, and spent time at the Interface Center Laboratory for Profibus in Fuerth where he was trained extensively on Fieldbus technology including Profibus and Profinet by Manfred Popp (the author of “Rapid Way to Profibus-DP).

He currently holds the position of service manager at Siemens for A&D where he’s responsible for technical support, online support, field service, repairs and spare parts.
Hertzog can be contacted on 011 652 3681 or hertzog.makete@siemens.com.

Take note:
• Ethernet requires enhancement to achieve realtime performance in automation.
• The ‘summation frame’ approach suits simple networks.
• The ‘individual frame’ approach suits most automation applications.

Continuous wave and pulsed radar transmitters are often compared for use in various applications. Recent developments have seen substantial improvements in both of these technologies, as epitomised in the products of the author’s company.

Take note:
• A high average transmit frequency is an important advantage in an FMCW device.
• A short pulse duration is an important advantage in a pulse radar device.
• A large dynamic range ensures accurate measurement even when signals are weak.

About the author
Thomas Musch holds a Dpil.-Ing. And Dr.-Ing in electrical engineering from the University of Bochum, Germany. From 1994 to 2002, he was a research assistant with a study group on high frequency measuring at the University of Bochum. Since 2003, he’s been employed with Krohne, Duisburg, in various positions. He currently heads the corporate research department.
Krohne can locally be contacted on 011 314 1391.

Up till now, optical networks have been reserved, mainly for long distances between large towns/cities. This situation has now evolved: Optical networks are no longer reserved for long distances. The demand for more and more bandwidth from end-users (ADSL, cable) is pushing the fibre optic line closer and closer to the subscriber. The lessons learnt are now proving valuable, even within industrial sites.

Take Note:
• Optical systems are becoming increasingly popular.
• Optical systems need proper maintenance and management just like copper systems.
• Optical network surveillance systems allow the detection of network faults.
• Network documentation systems facilitate proper network management.


About the author
Jean Ponchon, PhD Physics (University of Grenoble, France), began his career with JDSU 20 years ago as a software engineer. He then progressed to project manager for telecommunication test systems and has held the position of product manager for fiber optic monitoring system since 2000.
JDSU is locally represented by Comtest and can be contacted at 011 254 2200 or info@comtest.co.za.

Information systems provide an increasingly ubiquitous network within companies and offer services in new fields. Using this network, companies can provide faster and better services to their customers, including Radio Frequency Interface Device (RFID) and Voice over IP (VoIP) solutions. However, predictions made by research company International Data Corporation (IDC) show that changes in power supply and cooling in data centres will have a serious impact on both users and suppliers of data centre solutions.

This article will look at a summary of these predictions, and some of the challenges that IT professionals can anticipate.

Take note
• Over the next three years, 50% of large organisations will have an energy bill that exceeds their server bill.
• Data centre methodology of yesterday, conventional server technology and current requirements—together form the greatest IT challenge of tomorrow.
• New data centres should be more service oriented and be optimised for scalability, agility and resilience for improved future IT effectiveness.


About the author
Tony Day is the chief engineer, rack cooling, at APC for Schneider.
APC can be contacted on 011 465 5414 or Jacqui.gradwell@apcc.com

Spectacular television pictures with PC control
APC-IBM partnership offers scalable modular data centres
IO Link Master module in series production
Luminescence scale defines signal intensity
Weidmuller Profibus PA networking
Plug and play fieldbus display
Yokogawa's solution for turbo-machinery control
Multi-functional disconnect terminal blocks
Avoiding underground collisions by the nod of a cap lamp
New series of pushbuttons from GE
Compact, fanless, embedded controller
Signalling with Weidmuller
New operator interface from Rockwell

Sigloch Maschinenbau offers special machines for binding brochures and books. These range from gathering machines, adhesive binding machines, end-papering machines, to bookback gluing and back-lining machines, drying conveyors, nippers and ribbon inserting machines. The flexible individual components are integrated in a high-performance system. Moeller technology helps the automated machines achieve short resetting times, ensure convenient operation and optimum operational reliability.

Take Note
• When machines have to run continuously for years, it makes sense to use systems from suppliers that comply with high operating and safety standards
• Control cabinet size at Sigloch has been considerably reduced due to advanced wiring techniques and components.


About the author
Jose Ruivo has been actively involved in the industry for many years and currently holds the position of sales and marketing director of Moeller Electric in South Africa. Jose can be contacted on ruivo@moeller.co.za

The depletion of energy resources and the release of greenhouse gases into the atmosphere is of growing concern wordlwide. One area with huge potential for savings is in motors that operate fans, pumps and compressors. These are usually driven by fixed-speed motors, with the flow being controlled by energy-wasting throttling methods. Frequency converters cut out this waste by adapting the speed of the motor to directly match the required pressure or flow. #1 Take note • Motors consume around 30% of all the electric energy produced in the world. • About ¾ of all motors power pumps, fans or compressors are used in applications where energy consumption can be reduced through speed control. • Three-level inverter technology is re-used to allow excellent output waveforms to better control motor speed, thereby saving energy. #1 About the authors Pieder Jörg, Gerald Scheuer and Per Wikström are from ABB Switzerland. This article is re-published from ABB Review 4/2007 with permission. ABB can locally be contacted on 011 236 7000.

Power electronic systems in the voltage range of 1 200 V and higher, call for fully insulated signal transmission for both Pulse Width Modulated (PWM) and Integrated Gate Bipolar Transmitter (IGBT) status signals. In order to achieve sophisticated and repetitive signal transmission for all signals, including sensing signals, a fully digital driver core solution was developed to drive and control IGBT power semiconductors.

Take note:
• An electronic driver circuit drives the power transistors in a power electronic system.
• In the voltage range of 1 200 V, signal transmission systems must be fully insulated from the power electronics.
• Insulated digital signal transmission offers significant advantages over analogue transmission.
About the author
Markus Hermwille is the product manager for electronics at Semikron Elektronik in Germany. Semikron can locally be contacted on 012 345 6060 or karen.schutte@semikron.com.

How do you measure efficiency in motors? How do you ensure that only motors with acceptable efficiency are repaired? Can high efficiency motors be repaired? As efficiency and repair are two important factors that influence decision-making with regard to total cost of ownership; this article will consider the factors that influence efficiency and how these can be controlled.

Power shortages, sky-rocketing electricity costs, increasing fuel prices, and the environment playing havoc – all reasons why electricity has to be used as efficiently as possible: Hence, the drive to use high efficiency motors; ensuring that when motors are repaired, efficiency is maintained; and scrapping inefficient motors.

About the author
Henry du Preez has his BSc Electrical Engineering from Wits, MBL from Unisa, GED Electrical Engineering and Government Certificate – Electrical and Mechanical. Henry has over 46 years experience in the heavy engineering industry and mines and specialises in electrical machines and transformers. He is also a Fellow of the SAIEE.
Henry can be contacted on 083 252 7612 or henry@dupreez.co.za.


Take note
• The heart of quality and successful repairs on induction motors and armatures lies with the core testing.
• You only need one hot spot to cause an insulation failure, and only one failure to put the motor out of operation.
• If the repairer of a motor gets the core test wrong, or omits to do a test, and the core is bad or in poor condition – expect premature motor failure, low efficiency and increased costs to repair it.

Continued rise in demand for large motors keeps Alstom Electrical Machines fully stretched
RFC motor control gives Unidrive SP an advantage
Circuit breaker protection from CHI
Fenner reduces energy consumption with high efficiency motors
Middelburg welcomes Zest with open arms
Drive solution increases productivity at mine
New VSD for aircon industry
New features for Moeller circuit breakers
Pump motor protection
Comprehensive earth leakage protection
Zest at Electra Mining Africa 2008
Soft starter to control acceleration
Stepping up industry's energy efficiency

Ana-Digi Systems secures new distributorship
Buildworks acquires CONCO
Technical hotline assists industry
UKZN student wins Comtest prize
SEW X Series at Electra Mining
Yokogawa optimises engineering and services know-how
Zest acquires Enl Electrical
Making energy efficiency work for you
Powertech Transformers secures Eskom contract
Ampcontrol forges new horizons internationally

RBF switchgear for power plant
Grinaker-LTA completes Sasol contracts
Elquip acquires Pedrazzoli
Zest secures Lucy distributorship
AfroCentric indicates interest in Jacso
Alstom wins 'dog-boxes' frame contract
Honeywell opens Croatia office
Aberdare's new building investment benefits customers
ABB net income up 87%

We previously presented the benefits of Intrinsic Safety (IS) [1]. The definition of intrinsic safety used in the relevant International and Electrotechnical Commission (IEC) apparatus standard IEC 60079-11 is a “type of protection based on the restriction of electrical energy within apparatus and of interconnecting wiring exposed to the potentially explosive atmosphere to a level below that which can cause ignition by either sparking or heating effects”. This is a concise statement of intent to introduce a multi-faceted subject.

Take note
•Intrinsic safety allows safe ‘live working’.
•Instrumentation used in hazardous areas should be intrinsically safe.
•Ensure that you comply with the essential requirements of an intrinsically safe system.

MTL Instruments is locally represented by Extech Safety Systems and can be contacted through Gary Friend 011 791 6000 or garyf@tempcon.co.za.

With the evolution of power supply technology the design of power supply units has undergone some very distinct changes: physical size, layout and the working principle have all undergone major revamps over the years. When choosing a power supply a distinction must be made between regulated and unregulated supplies.

Conclusion
All switch mode power supplies monitor their own output for short circuits and have automatic switch-off for protection. In fact, this aspect could become problematic as the power supply will not only switch off the instrument, but the controller as well, when the same power supply is used to supply 24 V to both the plant instrumentation and controllers: the result could be that the whole plant goes down because of one loop’s short circuit.

This is where the selected fuse breaking technology comes in as a solution. The power supply output is wired through individual circuit breakers and the selected fuse breaking technology will then only switch-off the short circuit: the rest of the plant remains on-line. In addition, the fault finding is done for you: on inspection of the cabinet the loop that was switched-off by the power supply is immediately visible and can be repaired.

About the author
Lou du Plessis trained as a technician at Eskom Kriel power station. He currently holds the position of product manager at Phoenix Contact for the Interface product range which includes serial communication, relays, analogue cards, power supplies and monitoring relays. Lou can be contacted on 011 801 8200 or loudp@phoenixcontact.co.za.

Alstom Electrical SA acquires Current Electric
Containerising substations
Schneider MCCBs keep up with industry trends
Asset management through monitoring
Transforming to Powertech Transformers
Arc protection for Bangkok utility
Siemens pioneers the age of gas insulated switchgear technology

Control valves are used by pump manufacturers to assist with verifying the performance of their equipment as part of the final acceptance testing. The challenge of providing pumps capable of handling significantly higher pressures and increasing flow rates has led to the development of a new generation of designs.

Take note
• Controlling high pressures and flow rates simultaneously poses challenges for valve solution providers.
• Using power dissipation factor provides enhanced solutions for handling severe pump service applications.
• The success of power dissipation factor relies on control valve sizing, selection and a review of process conditions.

About the author
David B Martin is a chartered engineer (C.Eng.M.I.Mech.E) and has worked in the control valve industry for over 43 years. He has worked for two major control valve manufacturers and was technical director for one of these companies prior to forming Valve Solutions, his present company. He is the BVAA control valve training specialist and has also presented a number of papers world-wide on control valve related subjects.
Valve Solutions is locally represented by Spirax Sarco and can be contacted on 011 230 1333 or Debbie.groenewald@za.spiraxsarco.com.

Previously we considered two-port valves in detail [1]. In this article we will consider the more popular types of three-port valves. The article concludes with an overview of the use of two- and three-port valves.

Take note
• Three-port valves are used to mix or divert fluid passing through them.
• The types of control valves should be understood in order to choose the correct valve for a specific application.

About the author
The information used in this article was supplied by Debbie Robbeson from Spirax Sarco. Debbie can be contacted on 011 2300 or info@spiraxsarco.com.

Emergency-stop actuation
VAG Valves now in SA
Diaphragm for high temperature and steam applications
VAG Valves now in SA
Local company supplies valves to Norway
Valves and control products
Valves in three corners of South Africa
Modular vapour control