Climate change White Paper to be drafted by 2010
Avaya launches energy saving calculator
Cleaner energy - cooler climate
Africa not guilty yet most affected

Any system includes multiple circuit breakers. In a properly designed system, the right breaker must trip at the right time – and protect the system. This article reviews the cascading and discrimination requirements in a LV distribution system.

Take note
o Circuit breakers are always cascaded – which implies these are upstream and downstream devices.
o Discrimination of breakers implies that the breakers trip in an appropriate order.
o Generally the most downstream breaker (closest to the fault but upstream of it) trips first.
o Strategies exist to ensure proper discrimination.


About the authors
Marc Serpinet joined Merlin Gerin in 1972. In 1991, after managing a Compact circuit-breaker project, he was appointed head of the electromechanical design office for future developments. Robert Morel has been with Merlin Gerin since 1971. He took over development of Compact circuit-breakers and Interpact switches in 1980. He now manages the LV current interruption design office. Jean-Pierre Nereau started his career at Merlin Gerin. He is currently the manager of Schneider-Electric’s advanced design office.

When addressing safety critical control systems, Failsafe is the keyword that drives system designers to be ever more creative and system redundancy is a design concept that helps meet these regulatory requirements. Pressure transducer based systems must guarantee that systematic failures within hydraulic controls are eliminated and random error functions are identified so that all moving parts are shut down should a dangerous condition arise.

Take note

o Safety in the workplace is legislated and is becoming increasingly important.
o Automated load monitoring systems are being used to ensure safe working.
o There are transducers manufactured that are designed specifically for use in safety-related applications.

About the authors
Jürgen Reiser, a graduate of the University of Applied Science in Darmstadt, Germany, is product manager responsible for the mobile hydraulic pressure transducers in the TRONIC division of WIKA. Reiser was a control engineer in machine building before joining WIKA. Martin Armson is director in the TRONIC division at WIKA. He graduated as a mechanical engineer at Hertfordshire University in the United Kingdom and started his career in the research and development department with tractor mounted mobile hydraulics at Ransomes, Sims and Jefferies in England. He was involved in marketing and sales of pressure sensors with Honeywell before joining WIKA in Lawrenceville, Georgia.

Surge suppressor
Equipment leakage circuit breakers
New earth leakage protection relay
More power density - increased efficiency
Lasts longer, user-friendly
Surge, spike, line noise protection
Concrete poles for electrification project
ABCs on safety
How grand...Legrand
MOtor protection relays
Space and cost efficient terminal blocks
Admiral AX type 4 safety barrier
Modular multi-pole surge arresters

Photovoltaic (PV) solar is used as a primary alternative energy source, combined with wind power generation, to provide continuous power supply to the Equinox Mall (The Fountains) in Jeffrey’s Bay on the coastline of the Eastern Cape. Not only is this installation a trend-setting example for other large buildings in South Africa, but a positive example of what can be achieved by using alternative resources to supply energy. The technology is here, now, and is being successfully used locally, with proven results. All that is required is a change of mindset of developers to commit to sustainability and saving energy – and a few engineers to develop the concepts.

This article will look at the philosophy behind the green design of the Equinox Mall and will focus on how PV solar, wind energy, diesel generation and grid energy systems are combined through custom-engineering to deliver a successful energy efficient power supply, whilst serving as an effective power back-up system—achieving a 90 kW energy saving.

Take note
• Custom-designed low energy lighting ensured the optimal use of solar and wind energy at the Equinox Mall.
• From the outset, buildings should be designed to use less energy inefficient devices by maximising natural lighting and ventilation.
• High efficiency PV solar panels ensure high and cost-effective power output utilising less mounting space.

About the author
Yolanda de Lange has a diploma in journalism and was an editor with Crown Publications for over 12 years.

Proactive and innovative thinking has always kept one ahead of competitors. This is the approach First National Bank (FNB) used when deciding to conserve energy, by using a building management system in their Fairland building. With South Africa being in an energy crisis and considering the current economic situation, it is imperative to find ways to save electricity – and this involves a properly designed control and automation system. Take note o 90% of the electrical energy consumed in a building is for HVAC and lighting. o Proper energy management requires thorough control and automation strategies. o Building management systems offer significant opportunities for intelligent management of their energy usage. About the author Hercu du Preez started at SAM in 2006. He worked on software development and commissioning of Beckhoff PLCs to control the lighting at the Fairland building. He is currently working on software development and commissioning of a Siemens PLC to control a remote pump station at a mine in Zimbabwe.

PV solar training in South Africa
Finland's Inkoo - to become more efficient Adcock Ingram opts for Metasys
PlantPAx systems and solutions

The first part of this three-part article which appeared in the March 2009 edition of Electricity+Control, reviewed the SANS 20242-1 Amendment 6document in terms of the editorial amendments and corrections, amendments applicable to requirements for medical locations and amendments to the Certificate of Compliance (CoC) [1]. In this, the second part, we consider alternative supplies and generating sets. The third part will feature in the next edition of Electricity+Control. Take note: o Portable generators are being more commonly used and require consideration from a safety point of view. o Generators, themselves, formally lie outside the scope of SANS 10142-1. o Inclusion, electrically, of alternative supplies is covered in clause 7.12 of SANS 10142-1 but excludes co-generation. About the author After more than 50 years in the industry, Viv Cohen, in ‘retirement’, still consults for CBI –Electric as a Low Voltage Protection specialist and has also become involved in the training and conferencing circuit. He has been an active member of the SANS 10142-1 Working Group since its inception prior to 1978. In addition to being an SAIEE Council member, Viv represents the South African Institute of Electrical Engineers (SAIEE) on several SABS working groups and technical committees.

Industry's first 3U quad-core embedded controller
Engineering at its Centum best
Selecting photovoltaic systems for rural electrification: ARP 062-9-6 published
Development in flexible electronics
New AMEU president
Automation University

The simple act of moving a fluid through a pipe line or duct consumes energy, so in industry it is not unusual to associate flow measurement with energy consumption [1]. However, this article will argue that compressed air, steam and gas systems are systems that are often not adequately considered when energy transfer and efficiency of a plant is being considered. Take note: o A very large proportion of our industry requires compressed air, steam and gas to operate effectively. o Monitoring of electrical data alone will not provide sufficient information for proper energy management. o Gas flow monitoring is a critical component of a proper energy management system. About the authors Chris Gimson has worked for Endress+Hauser for 25 years. He is a Chartered Engineer holding a Bachelor of Science Degree in Electrical Engineering and a Masters Degree in Thermo Dynamics. Residing in Switzerland as project manager, Thermal, he is supporting the ongoing development and marketing of the new gas flow group. Frans van den Berg has worked for Endress+Hauser for the last nine years, starting as a project engineer. He is currently employed as product manager for Flow where all aspects of flow measurement - from product marketing and technical support, as well as application consultation and product selection -are handled by him.

Calibraiton rig in Switzerland
Variable area flow meter BGN
Small flow quantities
Compact design
Larox pumps cut costs and downtime
New from Microwave
Thermal mass flow measuring system
Exact industrial controls flow meter services
Solid state flow sensor in robust stinless steel housing
Ideal flow by Honsberg
Flow meters from ELIS PLZEN

Award for energy efficient GA compressors
Celebrating 25 years
RS-485 Fibre converter for industrial use
Hybrid encoded for longer life
Work with Eskom to reduce electricity-related injuries
Everything that counts
Rockwell acquires Rutter Hinz

Advanced and high-speed computer systems are allowing for huge SCADA systems to be configured, where large amounts of information are presented to the operator. This together with cell phones with instant messaging, the Internet, and other technologies provide what we believe to be an excellent infrastructure for process control. You can be in contact with your plant 24 hours a day, seven days a week. You can brush your teeth, listen to music on your Ipod and watch - in real time - your plant in operation on your cell phone, as well talk to your friends across the oceans.

However it is the author’s opinion that technology and the control systems of today are providing too much data and information. This is overloading the operators, which is decreasing their effectiveness and their ability to control the plant properly.

Take note
o Technology and the control systems of today are providing too much data.
o Operators faced with too much data are stressed unnecessarily and often face conflicting goals.
o Multi-tasking is not efficient.
o The trick is to configure a SCADA system to provide less information which can be done by a judicious selection and configuration of control tools.

About the author
Tony Lange is a registered professional engineer with over 25 years experience in process control and optimisation. He graduated cum laude in Electrical Engineering from Wits University. He obtained a PhD in Electrical Engineering, with specialisation mathematics and artificial intelligence. He is the managing director of Optin, a supplier of real time optimal and intelligent solutions and the South African agent for Gensym and other process control products.

Namibian water communication network
Sponsored SCADA system
Super relay PLC
Elquip goes for gold
CitectSCADA V7.10: upgrade Microsoft integration

New factory for Meissner
Getting the show on the road
Energy and business