Electricity + Control January 2019

FEATURES: · Control systems + automation · Drives, motors + switchgear · Energy management + environmental engineering · Lightning + surge protection · Pressure + level measurement + instrumentation

COMMENT

ON THE COVER

Welcome to 2019 May the noise be less and the inspiration greater!

A s we find with all new years, this one starts with many changes. Some may be subtle, others rather more obvious. It is an election year, and that always holds the promise of intrigue and excitement. However, I am confident that the noise levels may recede just a bit – and that we will get back on with the task of building the economy. When we reflect on where we have been as a country, it becomes easy to imagine that times have never been worse. That, of course, is far from the truth. There are indications that Basic Education is improving in some respects; and we know that, as a sector, our tertiary education institutions are very good – without exception. There seems to be growth in the Technical and Vocational Education and Training (TVET) sector – and just the other day I saw a newspaper headline expounding the virtues of aTVET education as opposed to a varsity one. These are interesting things to be seeing. It does strike me that our industry needs high-level technical skills – andmany of those skills do not require a university degree. In fact, our entire profession and our industry is built on the foundations laid by skilled artisans. Again, if we consider the pyramid of skills that drives our industry, we need to remember that it should be broader at the base: more skilled artisans than technicians; more technicians than technologists; and more technologists than engineers. Our engineering programmes at university are massively over-subscribed –

and whereas I do think there is no harm in over-producing engineers (unlike in some other disciplines…), it implies that we may be deploying engineers at inappropriate levels in industry – and hence not operating optimally. We need to broaden that base! With this comes the ever-present spectre of the 4IR. Will all these skills be replaced? Well, I have commented on this before – but I am of the view that some formally protected disciplines (such as surgery and law) are quite probably at greater risk than the dextrous skills offered by skilled artisans. Think about that. My suspicion is that the 4IR offers untold opportunity to the technical disciplines – where the full ambit of human skill and intellect are combined to solve problems, install systems, trouble shoot and repair. I am hopeful that youngsters see this – and that our industry is ready to honour all levels of skills within our disciplines. Success, after all, is a team sport. May I wish you the very best for this year ... and see what you can do to up-skill a young person. We need that.

FEATURES: · Control systems+ automation · Drives,motors+ switchgear · Energymanagement+ environmental engineering · Lightning+ surge protection · Pressure+ levelmeasurement+ instrumentation

EC_Jan 2019 cover.indd 1 12/13/2018 3:38:23PM www.electricityandcontrolmagazine.co.za

Beckhoff has a new EL3783 power monitoring oversampling terminal for high-resolution diagnostics of alternating voltages up to 690 V AC. (Read more on page 13).

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CONTENTS

6

Features

CONTROL SYSTEMS AND AUTOMATION 4 Smarter electrical control systems Joe Matheys, Rockwell Automation

6 Embracing automation in mining Interview with Simon Andrews, Sandvik South African Group of Companies

9 Make Industry 4.0 work for you Supplied by Nidec Control Techniques

11 Round Up

DRIVES + MOTORS + SWITCHGEAR 14 Wessels Mine cable belt conveyor upgrade John Proctor, Siemens

18 A technical guide to electrical braking: Evaluating braking power Supplied by ABB

22 Round Up

EARTHING AND LIGHTNING PROTECTION 24 DEHN Africa launches DEHNinsure Interview with Hano Oelofse 26 Lightning, load shedding and earthing Richard Evert, ELPA

26

27 Round Up

ENERGY MANAGEMENT AND ENVIRONMENTAL ENGINEERING 28 Pace-setting solar farm inaugurated at Otjikoto Arthur Tassell, Crown Publications

32 Round Up

34

PRESSURE + LEVEL MEASUREMENT + INSTRUMENTATION 34 A diamond in level measurement Supplied by VEGA Controls SA 36 Not a crack: Level measurement for natural gas Dieter Hägele, KSR Kuebler Niveau-Messtechnik AG

38 Round Up

Regulars

1

Comment

13 39 40 40

Cover article

Engineering the Future

Write @ the back

Events

2 Electricity + Control

JANUARY 2019

LSIS’ Green Drive Range

With their built in Future Smart Energy efficiency technology, the LSIS drive range is suited to all your AC motor needs 200VAC ~ 11 000VAC at 100W ~ 10 000kW

Why would one need to look anywhere else?

Product Features:*

- High Torque and Precise Control - HVAC Communication protocols - Fan and Pump control - Elevators and MRL range - Hoisting systems - IP66 protection - Marine Certification - Multiple Motor Control

With Proven installation yields of up to 60% in energy savings, LSIS is focused on a greener future for all. To cut peak tarrifs down to size, to improve power factor correction or just getting more efficiency from your plant then LSIS VSDs have the answer for you.

*product dependant

Ana-Digi Systems are import agents for LSIS Automation Systems in Southern Africa

Phone: 021-914 9030 24 (24 hours support) Email: info@anadigi.co.za www.anadigi.co.za

CONTROL SYSTEMS + AUTOMATION

Smarter electrical control systems

Joe Matheys, Rockwell Automation

System integrators can bring intelligent packaged power that integrates better with smart manufacturing operations than traditional electrical control.

Take Note!

Intelligent packaged power solutions provide access to electrical-system informa- tion. The Connected Mine can improve all areas of mining operations.

1

I ndustrial companies expect visibility into every aspect of new or upgraded plants, including their electrical control system. Now, the pres- sure is on system integrators to help connect these systems and make the real-time data availa- ble to workers. However, traditional electrical con- trol systems don’t easily integrate into connected operations. These hard-wired systems typically exist separately from a plant’s process control sys- tem. And often their data is only available in an e-house or substation, meaning workers need to enter potentially hazardous areas to access it. Facing these challenges, more system inte- grators are choosing to use intelligent packaged power solutions. These systems provide state-of- the-art digital technology that can integrate with a plant’s process control solution, unifying the two into a single architecture. The systems also pro- vide access to the electrical-system information that customers want, providing far-reaching busi- ness benefits for end users and integrators. Smarter systems About two-thirds of new plants use smart devic- es in their overall electrical systems, according to an ARC Advisory Group study. Digitally integrating

ergy intensity. Visibility into the electrical system can also help workers spot problems early, before they move downstream into the control system. For ex- ample, uneven electrical distribution system loading can shut down fans on catalytic converters. A networked system also can use remote ac- cess to the electrical system to enhance safety. Workers can access electrical system information or even open and close breakers from a remote computer or mobile device, without entering a high-voltage substation. Faster, better integration Traditionally, system integrators have had to devel- op custom programming for every electrical con- trol system. But some intelligent packaged power systems include standard, prebuilt faceplates that integrators can reuse across different projects. This can help them reduce programming require- ments and speed up integration times. The right technology vendor can also help inte- grators make sure that data from intelligent elec- trical devices (IEDs) is delivered at speeds custom- ers need. Using communications protocols such as IEC-61850 and EtherNet/IP™, along with inter- faces to legacy networks, a vendor can connect all IEDs and provide access to real-time information on equipment and operating conditions. Some vendors have even developed performance guide- lines to help identify how different systems will perform before they’re built. This can help system integrators reduce their design and testing times. A smart business model System integrators have a vital role to play in helping industrial customers become more connected and data driven.Those that can reliably and cost-effective- ly give customers access to information they need to optimise operations will have the most success.

2

all these devices can give end users access to infor- mation like faults, operating conditions, and alarms and events. This information can help workers more quickly iden- tify where, when and why an issue occurred so they can resolve it faster. This in- cludes the ability to observe power quality problems and unexpected increases in en-

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“One mining company improved production at a mine site by almost 15% ..."

The mining perspective The mining industry is certainly one that can stand to benefit greatly from improved visibility of pro- cesses, equipment performance and supply chain for smarter business decisions. Like many cyclical industries, mining is reviving, driven by steady global economic growth and an increasing demand for materials to support new technologies like electric vehicles, renewable ener- gy and mobile devices. Despite the optimism, the industry still faces major operational challenges in- cluding process efficiencies, cost control, worker health and safety, and skills gaps.To address these challenges, Rockwell Automation introduced The Connected Mine, leveraging the latest enabling and digital technologies. Using advanced analytics, The Connected Mine helps mining companies collect and aggregate data to gain end-to-end visibility into their oper- ations and make informed business decisions to improve mining operations. “One mining company improved production at a mine site by almost 15 percent by implementing a simulator that provides operators real-time recovery targets that are au- tomatically updated based on ever-changing feed grades,” says Fabio Mielli, market development manager, Rockwell Automation. “The Connected Mine concept provides our global mining custom- ers with the digital infrastructure needed to tap into exciting new technologies for optimised oper- ations.” The Connected Mine can improve all areas of mining operations. Extraction: Connecting and automating mobile assets and mine infrastructure – such as mine ma- chinery and ventilation – helps to make the extrac- tion process safer and more efficient. Process management and optimisation: The Connected Mine automates, controls and op-

timises mineral processes and metal refining operations, helping achieve greater throughput, enhanced recovery and better quality – all while reducing energy, water and reagents. Material handling: Smart machines like hoists, conveyors and stacker reclaimers improve materi- als handling by providing unprecedented access to data that can be collected, logged and analysed to help workers make better decisions. Mine electrification: A digital electrical system helps to enable seamless integration of power dis- tribution, motor management and process control, and captures the information needed for predictive maintenance and remote monitoring. Asset performance: Whether device-based or enterprise-wide, machine learning and scalable ap- plications that monitor the performance of critical assets and predict failures can help reduce equip- ment downtime. Worker safety and efficiency: Real-time mobili- ty and augmented-reality tools deliver timely, en- hanced visibility to field workers, helping to con- firm the right personnel have the right information at their fingertips. Mine-to-market integration: A powerful ana- lytics platform provides full visibility of the busi- ness, removing information silos, connecting dis- parate systems and applications, and informing better business decisions. Rockwell Automation has combined expertise in motor control, process, power and energy man- agement, and information solutions to deliver spe- cific and powerful solutions that address the most critical mining operational challenges. The Con- nected Mine is built on application expertise, and alliances with best-in-class system integrators, equipment manufacturers and technology provid- ers with strong execution capabilities.

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Embracing automation in mining

There is a growing move towards the automation of underground mining operations. This is the view of Simon Andrews, Vice President – Sales of Sandvik Mining and Rock Technology Southern Africa and also MD of the Sandvik South African Group of Companies. He says the mining industry is ever more receptive to the concept of automation and believes that a ‘tipping point’ in market acceptance is likely to be fast approaching.

Take Note!

Streams of real time data can be analysed to detect trends. Automation presents the opportunity for mines to employ a more diverse workforce.

1

2

A utomation is part of a broader trend to- wards the ‘digitalisation’ of mining. “Within Sandvik, we see digitalisation as a means of leveraging digital technologies to drive efficien- cy and profitability,” says Andrews. “Most of our machines are now equipped to generate streams of data in real time which can then be analysed to detect trends, improve performance and enhance maintenance. But digitalisation also encompasses the full or partial automation of mining operations, also known as autonomous or semi-autonomous mining, and this is ultimately where the biggest gains are likely to be made. “We’ve noticed an incredible interest in our dig- italisation and, in particular, our automation tech- nologies over the past year,” Andrews continues. “Increasingly, customers are seeing automation as being business critical. With deeper mines, nar- rower deposits and generally more difficult mining conditions, costs are steadily going up. The only way that much of the mining industry is going to

survive is by increasing its efficiency through auto- mation and other technologies.” Andrews attributes the change in attitude in part to the emergence of a new generation of mining engineers and managers, who have been brought up with smart phones and the Internet and who are entirely comfortable with new technology. Full-blown autonomous mining installations around the world are still relatively rare but they do exist and have generally proved successful. An ex- ample in South Africa is the Finsch diamond mine in the Northern Cape, where a fully automated trucking loop has been operating for well over 10 years. Sandvik was the supplier of the technology, which included a fleet of six ‘driverless’ trucks. “One of the reasons there has not been a big- ger uptake of automated mining technology thus far in Africa – and indeed worldwide – is that there has been a dearth of new mining projects over the past several years,” says Andrews. “The tech- nology is best applied in greenfield projects. The

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good news is that we have a number of large new underground mines on the way across the African continent which will all use bulk mechanised min- ing methods and which will probably all be auto- mated to a lesser or greater degree.” Projects in South Africa which lend themselves to mechanised – and potentially autonomous – mining methods are the Venetia Underground Project of De Beers in northern Limpopo Province, the Platreef project of Ivanhoe near Mokopane and the Waterberg project of Platinum Group Metals, north of Mokopane. Further north in Africa, Ivanhoe is developing its Kamoa/Kakula copper project in the DRC which will see highly mechanised underground mines being established, while Resolute Mining is on re- cord as saying that its new Syama underground gold mine in Mali – which it describes as a ‘mine of the future’ – will feature a high degree of mech- anisation and is amenable to automation. In Ghana, AngloGold Ashanti is planning the redevelopment, at a projected cost of US$450 to US$500 million, of its Obuasi mine. In a recent announcement on the proposed redevelopment,

A tipping point in market acceptance of automation is fast approaching.

for mines to employ a more diverse work force. “Traditionally, miners who work underground have had to be physically strong. Automation removes this requirement and could result in more women, for example, being attracted to careers in mining,” he notes. “It also opens the way for older people, who find an underground environment too de- manding, to be employed.” Better asset utilisation is another benefit as machines are able to work longer hours with less of the wear and tear associated with manual op- eration. “Typically, one needs fewer machines to do the same amount of work and those machines

it said the project “envisages a smaller but skilled workforce that can operate in a mechanised/au- tomated operation with a strong sense of accountability”. Apart from increased produc- tivity, a key benefit of automation is safety. “Obviously, automation takes operators out of the un- derground work space and puts them in air-conditioned control rooms on surface. With fewer people needed underground, the potential for accidents to occur is substantially reduced. In ad- dition, the lapses in judgement which can come from operators sitting in the cabs of machines and becoming fatigued are all but eliminated,” says Andrews. He adds that automation also presents the opportunity

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CONTROL SYSTEMS + AUTOMATION

will generally have longer life-spans,” Andrews ob- serves. He acknowledges that automation is often as- sociated with job losses. “We think this fear is unfounded. One can even look upon automation as a form of job creation as it allows mining to go into areas that were previously regarded as unsafe and/or uneconomic. Nevertheless, it’s absolutely imperative to address the very genuine concerns and engage with employees and the unions when planning the introduction of automation.” Sandvik’s key offerings when it comes to the ‘digitalisation’ of mining are its OptiMine ® and AutoMine™ systems. OptiMine ® is a modular in- formation management solution that offers a re- al-time view of underground mining operations while AutoMine™ is a product family that covers all aspects of automation from tele-remote or au- tonomous operation of single pieces of equipment through to the autonomous operation of entire fleets of trucks and loaders underground or drill rigs on surface. OptiMine ® modules include 3D Mine Visualiser, which can provide a three-dimensional model of an entire mine; Drill Plan Visualiser, an easy-to- use tool for the visualisation of longhole drilling and rock support; Scheduler, an efficient graphical scheduling and resource allocation tool; Location Tracking, which provides accurate real-time loca- tion data for machines and equipment; and Mon- itoring, which updates equipment information au- tomatically in real time. The AutoMine™ modules range from the en- try-level Tele-Remote package through to Fleet, which is a highly advanced automation system for a fleet of underground loaders and trucks sharing the same automated production area. While Andrews is enthusiastic about Sandvik’s digitalisation offerings, he emphasises that the group recognises that not all customers want or need the technology. “Interestingly, we recently launched our LH115L 5-tonne, low-profile loader, which we’re manufacturing here in South Africa in a new manufacturing facility. This is an ‘ana- logue-type’ LHD that meets a clear market de- mand for simple, straightforward machines with- out too many ‘bells and whistles’. We understand that there are two markets to address and we have the machines and systems for both,” he con- cludes.

SANDVIK SHOWCASES DIGITALTECHNOLOGY AT MINING INDABA Sandvik Mining and Rock Technology will be exhibiting at Mining Indaba, which takes place at the CapeTown International Convention Centre (CTICC) from 4 to 7 February 2019. Visitors to the show are invited to get first-hand information of the company’s digital mining technology by speaking to Sandvik experts on the stand (Stand 104, near Entrance 2).

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Make Industry 4.0 work for you

Some organisations may be fully embracing the benefits of Industry 4.0 while for others the grand idea is a fair way off. Even so, there are still plenty of opportunities to be had in the short term. In research conducted by Nidec Control Techniques, many respondents noted that operational efficiency was their customers’ highest concern. This is indeed an order winning factor and one that is quite easy to achieve, even without significant investment.

Take Note!

1. Changes in technology are helping to address bigger issues such as skills shortages. 2. Using Industry 4.0 allows you to analyse and sched- ule preventative mainte- nance. 1 2

T oday, even general purpose drives can run with Ethernet or RS-485 (in conjunction with a PLC) to provide data analysis. In fact, in- dustrial Ethernet has been described as the back- bone that connects all parts of a manufacturing business – from office to shop floor, and remote locations. The basic information we’re receiving down the cable might not be ground-breaking from a technological perspective, but it gives feedback from critical components such as the drive. That means you can monitor real-time data in-situ, from a directly mounted HMI, networked computer, or remotely over a VPN (Virtual Private Network). This level of connectivity makes it possible to analyse information from a range of machines within one factory. We can analyse aspects like cycle time, power usage, current or any other variables, helping to quickly identify and address production slippages associated with equipment failure over time. As a manager, this data is invaluable. The re- search found that when users have access to “lo- cal” information in the factory, it is quick and easy to cross-check compliance with production stand- ards such as total productive maintenance. Reflec- tive analysis of data empowers customers to take

a proactive approach to preventative maintenance without high levels of technical ability.

Building on the foundations of I4.0 In the research we also found that while many companies could appreciate the coming changes in technology, they were holding back from inte- gration. A notable issue being the cost of imple- mentation versus the perceived benefits. The maturity of the machine building market has meant that companies are looking for different ways to improve their products. One of the most profitable ways to do this is to offer additional ser- vices, such as preventative maintenance. This alleviates a significant pressure for cus- tomers. It also enables a huge opportunity for rev- enue generation with the introduction of externally monitored systems. Sharing production data gives the customers the peace of mind that experts are watching over their systems. More importantly, changes in technology are helping to address bigger issues like ageing populations and skills shortages. Both of these aspects are high risk for manufactur- ers. That’s because technology is moving quickly, and we simply don’t have enough specialists in the world. This is where manufacturers can help.

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only data. Nonetheless it exposes a significant dif- ference in attitude. That attitude is changing though, and it mostly depends on the level of investment. You already see cloud-based CRM systems used for capital equipment such as wind or solar plants. It makes a lot of sense to do so. Breakdowns have a huge cost implication. If you take Rolls Royce aero en- gines as a further example, everything is logged back to the manufacturer who uses the data to manage the engines and perform servicing. Because of the success of Industry 4.0 in high value applications, we’re beginning to see the democratisation of data to lower value capital equipment. That is set to be a game changer as data will be logged continuously all the way down to individual motors, giving a rich picture of how well equipment is operating. In the short-term, those who are wary of cloud- based set-ups can benefit from remote monitoring instead. Logging in over a VPN means your cus- tomers can benefit from fast diagnostic support, and you reinforce the real value of your relation- ship going beyond the initial sale. In addition, you remove costly site visits to your customer, espe- cially throughout the warranty period. Overcoming pain points One of the biggest barriers to the growth of Indus- try 4.0 is the lack of standardisation. This is a big is- sue when we consider a connected factory and the lack of compatibility between systems and compo- nents. It is for this reason that customers are con- sidering open systems to enable Industry 4.0 driven technology in their businesses, particularly around the areas of communications protocols. KEY POINTSTO NOTE 1. Almost all businesses can gain from simple In- dustry 4.0 integration. 2. While the initial investment of time is required to develop your platform, there are sufficient benefits in both revenue growth and customer service to justify the upfront expense. 3. Although cloud software is beginning to help Industry 4.0 realise its potential, remote ac- cess over VPN is a viable entry point for small and large businesses. 4. Consider which manufacturers provide open communications protocols to ensure compat- ibility and ease of integration.

There is an amount of fear involved in data security around cloud software.

For many businesses, maintenance provides a highly profitable revenue stream. It also gives you an opportunity to keep in contact with your cus- tomer. Using Industry 4.0 technology allows you to analyse and schedule preventative maintenance so you can utilise your workforce efficiently. The same goes for stocking spares; why hold high stock levels on the shelf when the system can flag your requirements as you go? Industry 4.0 technology also provides data to support future sales of upgrades to existing cus- tomers. That’s the same information you’re using to prevent breakdowns. Over time, this presents you with an opportunity to justify their investment into upgraded equipment. The data also provides the hard evidence to combat aggressive perfor- mance statements from competitors, which your customer may take at face value. A cloud too far Our research suggests that there is an amount of fear involved in data security around cloud soft- ware, and that’s understandable. In recent years, there have been some huge breaches in security. In the future though, our interviewees suggest that everything will operate on the cloud. Most businesses already feel comfortable placing sen- sitive information such as customer names, infor- mation and quotations in a cloud-based CRM (Cus- tomer Relationship Management) system. The difference is that a security breach on a machine has the potential to cause injury, while a CRM is

This White Paper was supplied by Nidec Control Techniques (www.unidrivem.com), a leader in the evolution of electronic mo- tor control.

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CONTROL SYSTEMS + AUTOMATION

EtherCATTerminals for mains monitoring, process control and power monitoring Energy management in machine operation and in the energy in- dustries creates a range of demands, starting with basic monitor- ing of the supply network and process control to high-end power monitoring. In response to these demands, Beckhoff has added four new EtherCAT I/O terminals to its existing product range, making a broader range of EtherCAT Terminals available. at 50 Hz. Four electrically isolated current measuring channels with freely adjustable measurement ranges for 100 mA, 1 A or 5 A, with a surge current capability of 60 A, are available.

Two further EtherCAT Terminal innovations have been designed for energy management in monitoring and maintenance applications: • As an economy version, the EL3423 three-phase power meas- urement terminal is intended for cost-sensitive energy manage- ment solutions, especially in IoT applications. The parameters that can be measured are energy, power and a mains quality fac- tor.These are recorded with an update interval that is adjustable from 10 s to 1 h. As a special feature, the measured parameters are available as average, minimum and maximum values. • The EL3483 three-phase mains monitoring terminal for volt- age, frequency and phase enables optimum monitoring of the power supply to a machine, which is particularly advanta- geous for systems that are sensitive to voltage variations. The functions include threshold value monitoring of the internal measured values, and setting of warning and error bits in the process image. Single-phase operation as a voltage, frequen- cy and phase monitor is also possible. Enquiries: Michelle Murphy.Tel. +27 (0) 11 795 2898 or email michellem@beckhoff.co.za

Together with the proven EL37x3 power monitoring oversam- pling terminals (and the associated TwinCAT Power Monitoring software library), the new EtherCATTerminals for energy manage- ment provide a comprehensive product portfolio that can be opti- mally adapted to the varied tasks found in a range of applications. Two of the new EtherCATTerminals are ideally suited for power measurement in process control applications: • As the new standard power measurement terminal, the EL3443 three-phase EtherCAT Terminal is universally suitable for all process control tasks. It offers numerous new functions such as mains monitoring functionality, precise determination of zero voltage crossing and harmonics analysis. In addition, it is also suitable for dc systems. • The EL3453 three-phase EtherCAT Terminal for measuring volt- ages up to 690Vac focuses on more demanding process control tasks. For this purpose, the terminal updates its process values with every half-wave, which corresponds to an interval of 10 ms

Ongoing evolution keeps Booyco PDS fit for purpose

A third zone can also be defined, in which the pedestrian’s presence will automatically trigger an electrical or mechanical interven- tion that reduces the vehicle’s speed to a crawl and even to a complete stop. Further enhancing the fit for purpose status of these technologies is the Booy- co Controller Interface to integrate all the deployed sensing systems; the company also has a range of test equipment for the systems and their applications, ensuring optimal uptime and safety impact. Enquiries: Anton Lourens.

In line with the Mine Health and Safety Act’s regulations on machinery and equip- ment, the onus is on mines to ensure that their proximity detection systems (PDSs) are ‘fit for purpose’ when it comes to pre- venting collisions between trackless mo- bile machines (TMMs) and pedestrians. In terms of the 2015 gazetted regula- tions, the employer must take ‘reasonably practicable measures’ to ensure that pe- destrians are prevented from being injured as a result of these collisions. The regula- tions also stipulate certain requirements regarding warning systems to pedestrians andTMM operators, and automatic means of retarding speed and braking on TMMs. This focus on compliance has kept Booyco Electronics at the forefront of technology development, innovating in- creasingly effective products to enhance safety and asset management on open- cast and underground mines. As a pio- neer in proximity detection, the company produces a range of solutions including interventions in vehicle operation to help prevent accidents and injury. The Booyco Electronics’ PDS warns pedestrians of an approaching vehicle and alerts the TMM operator that a pedestri-

an is within dangerous proximity of the vehicle. Using very low frequency (VLF) technology to generate a magnetic field around a vehicle proved to be a break- through in underground safety, as the VLF signal could propagate through the under- ground rock to identify hazards even be- fore they were visible to the pedestrian or operator. Both the pedestrians and drivers carry a personal communication tag which is activated when entering a warning zone around moving machinery. As mining regulations have raised the bar in terms of fit for purpose require- ments, so Booyco Electronics has evolved its PDS systems to provide feedback into TMM control systems.This is done through the creation of ‘zones’ within the magnetic field which trigger specific actions. The proven accuracy of the technology can define these zones precisely. A first zone of safety, for instance, may be 20 m from the moving vehicle, and is accurate to within 10 cm. A receiver and buzzer unit carried by the miner alerts them if they en- ter a dangerous area, even when out of sight of the vehicle operator, who is then warned if the pedestrian enters a second zone, closer to the vehicle.

Tel. +27 (0) 66 126 6926 or email anton@booyco-electronics.co.za

Using VLF technology underground, the Booyco PDS has proved its reliability.

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CONTROL SYSTEMS + AUTOMATION

PremiumVFD control for HVAC and pumps

PC setup using the DriveView7 integration software freely available from LSIS. Further options include features such as pipe fill, pipe break, pump clean, and motor pre-heating.. The Fire Mode option is designed for fire emergencies where fan control and exhausting are necessary and the mo- tor needs to keep running no matter the condition of field devices communicating with the drive. Should an event occur that results in the failure of the inverter’s oper-

complies fully with international standards such as UL, CE and EAC quality and elec- tromagnetic compatibility standard. With this standard drive the operation temperatures are rated up to 50°C at 90% humidity without condensation, making the LSLV-H100 range a robust, cost-effec- tive power saver that complements any well-designed system. Enquiries:Tel. +27 (0)11-704 0144, +27 (0)21-914 9030, +27 (0)31-903 1627; Email: info@anadigi.co.za

With the implementation of HVAC sys- tems, demands for proper control and safety are becoming less of a choice and more of a necessity. The LSLV-H100 offers features unique to HVAC and pump systems. Unlike a mul- tipurpose drive, this VFD specifically focus- es on applications for the water reticulation and ventilation industries and has many new functional features. Using MMC (Multiple Motor Control), the H100 as master can start up to five auxiliary motors with PID control to bal- ance the pressure in a system. There are also two analogue and one pulse train input and two analogue outputs with an open collector pulse output as standard. Added to this are seven programable dig- ital inputs and five programmable outputs including a NO/NC output. With the RTC (RealTime Clock), calendar set dates and time set points can be im- plemented without using external devices such as PLCs and timers. The RTC and set- tings are not installed in the keypad but in the control board, thus allowing the drive to run with or without the keypad. The keypad, which is designed for HVAC use, is able to store the drive parameters, thus enabling easy transfers from one drive to another. There is also a USB programming port for

ation, the H100 will perform a reset and restart to con- tinue the operation until either the mo- tor or the drive fails completely. Communica- tion protocols are not limited to the standard RS485 but include BAC- net MS/TP, Mod- bus-RTU, Metasys N2, and the option of LonWorks which can be added. For peace of mind, the LSLV-H100

Electrical upgrades at Zululand Anthracite Colliery EMIS 2002, part of Becker Mining SA, has completed upgrade projects at Zululand Anthra- cite Colliery (ZAC) near Ulundi in KwaZulu-Natal, which encompassed the design and instal- lation of communication, automation and protection systems, for improved productivity at the plant. “These projects involved the upgrade of existing switchgear at the plant substation and the installation of communication, automation and protection systems at the mine’s MacNel- ly Plant. Becker Mining was also responsible for the design and installation of advancements at the mine’s main washing and siding plants, as well as the establishment of a leading-edge control room,” said Frikkie Quirk, Senior General Manager, Electrical: Becker Mining South Africa. “All Becker Mining’s upgrade projects for ZAC, which were installed and commis- sioned on time, have resulted in improved efficiencies, greater productivity and energy sav- ings on the mine.” Apart from the design and manufacture of a wide range of electrical products for haz- ardous and non-hazardous applications, Becker Mining South Africa also offers a repair and maintenance service to ensure total reliability of equipment in harsh operating environments. Becker Mining SA’s specialist services to the mining sector include energy distribution, communications and automation solutions, mechanical and transportation systems and steel arch roof supports. Enquiries: Frikkie Quirk.Tel. +27 (0) 11 617 6300 or email info@za.becker-mining.com

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COVER ARTICLE

High-precision grid analysis within the EtherCAT Terminal system

FEATURES: · Control systems+ automation · Drives,motors+ switchgear · Energymanagement+ environmental engineering · Lightning+ surge protection · Pressure+ levelmeasurement+ instrumentation

EC_Jan2019 cover.indd 1

12/13/2018 3:38:23PM

B eckhoff has a new EL3783 power monitoring oversampling terminal for high-resolution diagnostics of alternating voltages up to 690 V AC. Conventional automation and power measurement technology are increasingly converging. With the integration of the new Beckhoff EL3783 oversampling terminal for power monitoring into standard control systems, high-precision grid analysis becomes available for power-generating systems. Most importantly, 3-phase AC voltage systems up to 690 V can be analysed simultaneously on six channels and with 20 ksamples/s directly in the PLC. For each of the three phases, the EL3783 EtherCATTerminal fromBeckhoff samples voltages up to 400/690 Vrms and currents up to 1 or 5 Arms as instantaneous values with 16 bit resolution. The six terminal channels are evaluated simultaneously based on the EtherCAT oversampling principle, with a temporal resolution of 50 µs, i.e. significantly faster than the cycle time of the controller. Using the EtherCAT distributed clock's functionality, it is also possible to measure synchronously (<< 1 µs) with other EtherCAT devices in systems of virtually

any size and precisely detect propagating grid faults, for example. Extensive data with relevant details are available in the control system if true RMS and performance calculations or complex user-specific algorithms are used to analyse the voltage and current curves, for instance. In addition, the EL3783 EtherCAT Terminal achieves 650 % of the nominal 1-ampere measuring range through automatic current range switching, offering high accuracy with a maximum measurement error of only 0.2 % (of the full scale value). In conjunction with TF3650, the TwinCAT 3 Power Monitoring library, the EL3783 Terminal represents a highly dynamic measurement system for detailed network analysis that is seamlessly integrated into standard PC-based control technology. In this way, requirements for network supporting measures in the event of voltage drops (LVRT, LowVoltage RideThrough) can be identified, for example, or harmonics analysis can be used to implement condition monitoring without additional costs for acceleration sensors.

Enquiries: Michelle Murphy,

Tel +27 (0) 11 795 2898 or email michellem@ beckhoff.co.za

The EL3783 power monitoring oversampling terminal from Beckhoff provides detailed current and voltage values for 3-phase power grids up to 690 V AC, while meeting demanding requirements in wind turbine applications.

Electricity + Control

JANUARY 2019

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DRIVES + MOTORS + SWITCHGEAR

Wessels Mine cable belt conveyor upgrade

John Proctor, Siemens

Siemens, in partnership withTech Edge, is in the process of upgrading the cable belt conveyor at Wessels Mine in the Northern Cape. Wessels Mine hauls manganese ore from the underground crushing plant to the surface using the cable belt convey- or. The existing system was installed in 1979 and, to maintain reliability, the mine de- cided to upgrade the entire drive train (drive wheels, gearboxes, motors and drives).

1. In December 2017, South32 placed the or- der for the upgrade of the cable belt conveyor drive train. 2. The drive wheel and idler wheel dimensions have been matched exactly. Take Note! 1

Introduction In December 2017, South32, the owners of Wes- sels Mine, placed an order with Siemens for the upgrade of the cable belt conveyor drive train. The aim of the project was to extend the life of the cable belt for another 25 years. The existing con- veyor infrastructure will remain unchanged while the drive wheels, gearboxes, motors and drives will be upgraded. After multiple discussions with the customer, it was decided to extend the scope of the project to include a new MCC and 3.3 kV switchgear. Siemens has completed the factory accept- ance testing and when civil works are completed in early 2019, the company will able to complete the implementation. What is a cable belt conveyor? A cable belt conveyor has two steel cables that support the conveyor rubber belt. These steel ca- bles are driven by drive wheels and not the con- veyor belt itself as per standard conveyors. The rubber belt is folded over at the tip point and re- turns on the bottom ropes back down the mine. It is possible to have multiple conveyor flights using the same steel cables. The rubber belt has two pairs of grooves; the bottom grooves support the rubber belt and ore extracted out of the mine, the top grooves are used for the return trip back un- derground. Existing system The existing system uses a limited slip differential gearbox (see Figure 1 ) to achieve speed matching between the two steel cables. The cable belt is driv-

en by two 710 kW motors started Direct on Line (DOL) with fluid couplings and stopped by four hy- draulic brakes on each side.There is an idler wheel in front of the drive wheels (see Figure 2 ) to increase the wrap angle of the cable over the drive wheel.

Basic information on the cable belt conveyor

Cable belt information Item No Description Quantity Unit 1 Installed Aug-79 2 Total length 1675 m 3 Conveyor sys- tem length 3316 m 4 No. of conveyor flights 2 5 Angle 14.5 degrees 6 Vertical lift 392 m 7 Capacity 880 MT/h 8 Load design 84.2 Kg/m 9 Belt speed 3.3 m/s 10 Drive wheel size 3300 mm 11 Drive wheel rope wrap angle 230 degrees 12 Rope diameter 45 mm

Figure 1: Limited slip differential gearbox.

Existing system

13

Motor - voltage (two motors) Motor - power Motor - speed

3.3

kV

14 15

709 988

kW

Figure 2: Existing drive and idler wheels.

rpm

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DRIVES + MOTORS + SWITCHGEAR

Overview of the upgrade solution The existing systemmust remain operational while the new system is being installed. After much de- liberation it was decided to install the new drive wheels behind the existing system. In order to balance the forces on the conveyor sheave wheel tower, the angle of the conveyor cables from un- derground should be similar to the angle descend- ing to the drive house. The drive wheels have to be placed as close as possible to the existing system. The inherit requirements of the new system are: • Speed matching of the conveyor ropes. • Fail safe braking systems. • ‘Soft’ starting of the conveyor. The customer also wished to achieve the following objectives: • A level of redundancy with respect to the main equipment to reduce down time. • Safety required: o Anti roll back on conveyor. o Safety guards with gate interlocks to trip conveyor if breached. • Lower conveyor speed until conveyor tail take- up has occurred. • Be able to utilise both the old and new drive wheel installations. System calculations From the source information and gearbox ratio, the following was calculated:

A single SCADA station will be used to control the plant. A main desk is installed as a maintenance location.

Figure 3: Drive wheel and idler wheel.

To increase redundancy with the braking system, the following will be implemented: • Dual hydraulic braking lines. • Four low speed brakes on each drive wheel (top two on one braking line, bottom two on the other hydraulic braking line). • High speed brakes on a disk between the mo- tor and gearbox (north and south). The brakes used are: • Brake stands (drive wheel) – Svendborg brakes BSFI 3120 96 kN brake force. • High speed brakes – Svendborg BSHF 330 24 kN brake force. Planetary gearboxes have been chosen because of their highest known torque density superiority. The down side of using planetary gearboxes is having to add gearbox coolers. Anti roll back devic- es will be installed into both gearboxes. Electrical solution The main components are: • New 3.3 kV switchgear – completely replacing the existing switchgear. • Drive transformers – double secondary windings DyN11 & Dd0 – 30 degrees phase shift to reduce harmonics – 3 MVA, 3.3 kV / 0.69 kV – two trans- formers will be installed for redundancy. • Drive change-over panels for swopping drive transformers. • NewMCC transformers 350 kVA, 3.3 kV/0.4 kV Dyn11 – two transformers will be installed for redundancy. • Variable speed drives – Sinamics G150 900 kW with braking resistors – two drives. • MCC – two Incomers – only one Incomer ACB will be installed – swop position to the other cradle to change transformer supply. Detailed information on variable speed drives and speed control: • Two parallel converters per drive – one con- nected to the star winding of the transformer

1 Rope pull per side (full load)

17.5 tons

2 3

Accelerating power

141.6 kW 567.5 kW

Power required for load

4 Power (friction) (5% of load)

28.4 kW

5 6

Drive size - required

737.6 kW 900.0 kW

Actual drive size

The following equipment will be installed: • Gearbox: Ratio – 89.75; Torque – 684 kN.m. • Motor: Dual winding – 790 kW; Four pole – 690V. • Variable speed drives: 900 kW, 690 V. Mechanical solution The drive wheel and idler wheel dimensions have been matched exactly, as have the relative posi- tions between the drive wheel and idler wheel to achieve the same wrap angle. The JVL lining on the drive wheels is identical to the existing sys- tem, alternating with polyester and aluminium.

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DRIVES + MOTORS + SWITCHGEAR

• Remote IO – Flex IO. • Profibus as main Fieldbus.

and the other to the delta winding to reduce harmonics. • Additional controllers added to be able to run each of the parallel drives separately – level of redundancy. • Speed measurement – encoders on the mo- tors, encoders on the idler wheels to measure rope speed. • The aim is to keep the rope speed identical, as the liners wear, and to do load sharing be- tween the drives. • Speed modes – jog (forward only), crawl, and run. • The speed matching solution is realised by us- ing variable speed drives and there will be no mechanical coupling between the two steel cables (north and south ropes). Control solution A single SCADA station will be used to control the plant. A main desk is installed as a maintenance location and to provide redundancy if the SCADA stations fails. There are four modes of operation: automatic mode, manual mode, desk mode and local mode. The standard operation when a run is selected is to run the conveyor at crawl speed until the take- up at the tail has occurred and then accelerate the conveyor to the selected run speed. The drives will monitor the line speed of each rope by using the encoders on the idler wheels, this will be used to do speed matching. The drives will also do load sharing by monitoring the torque of each drive. Equipment to be used for the control is as follows: • CTI PLC / Citech SCADA.

There are four modes of operation: automatic; manual; desk; and local.

• Remote IO in each MCC starter and MV feeder. • Main desk with Operator Panel (CTI) with standard pushbuttons for common functions. Benefits of the new system • Safety – anti roll back, 400% braking capacity of each drive wheel with dual channel system and high speed brakes. • Expect more even liner wear with load sharing and speed matching. • With the drive doing dynamic braking there is reduced wear on the brake pad and the brake path. • Easier fault finding – new MCC, MV panels, PLC software. Conclusion The safety requirements of the customer (braking, anti roll back and safety barrier) will be completely implemented. The speed control and soft starting of the conveyor will be tested on site and be com- pletely implemented. A fully redundant system was never envisaged but a level of redundancy will be achieved with the following elements of the system: • Drive transformers – one active/one installed in stand-by. • Change-over panels to connect the drives to the other drive transformer. • Run 50% conveyor capacity by using only one motor winding, using the additional drive con- trol units and only one converter block per drive. Acknowledgements The author would like to acknowledge the follow- ing people: • Bannister Erasmus – Tech Edge (Design of me- chanical solution) • Roberto Robbetse – South32 Wessels Mine (Customer) • Keith Milford – JVL Industries (Design assis- tance) Resume John Proctor has a BSc Electrical Engineering de- gree from the University of Cape Town. He has an MDP in Project Management from UNISA, and has worked at Siemens Ltd for 30 years.

Figure 4: Factory acceptance setup.

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