Electricity + Control June 2017

FEATURES: • Pressure + level measurement • Cables + accessories

• Control systems + automation • Electrical protection + safety • Plant maintenance, test + measurement

COMMENT

I meet regularly with friends from industry. Obviously there are common themes to our discussions, but education and the fu- ture come up regularly. And (some may say surprisingly) so do conversations about successes and gains, and how industry has in many cases reinvented itself to respond to the changed environment in South and southern Africa. Equally, there are those who hanker for the good old days – days that I have come to recall more as a mirage than a reality. Frankly, in the cold light of day, when were the old days really good? Many still believe they were. Allow me to reflect on some of the positive engagements I have had recently. These relate particularly to actual interactions I have had with leaders of our industry, whose companies continue to grow and prosper – largely because of the self-belief that their leadership has in the company. As a mere aside, I note that all of these interactions have included an affirmation that the company has toward the upskilling of staff – and of its customers. This resonates with me, because an informed client is the best client; and the more you can upskill your own staff, the better off your company will be. It seems almost bizarre, after the above comment, that I still engage with people who think that to upskill staff – and then see them leave – is the end of the world. Obviously, one would like to retain all skilled employees but sometimes that is not possible. I have seen a wonderful comment where the CFO remarks on the risk of investing in the training of staff – and they leave. The CEO responds: “What if you DON’T train the staff – and they stay?”

The second point I would like to make is that these companies share a fundamental belief in their own brand. This is a belief engendered by the executives of the company – and seemingly a reality taken on board by the staff. This is an obvious point to make – but I find many companies where the discussions are invariably about how bad things are, and how difficult it is to succeed. And I fully appreciate that. The trouble is that this tendency to see all the obstacles ends up being the establishment of a rather defeatist attitude amongst the staff – to the extent that the company begins to decline, rather than the rise above it all. Nobody living and working in South African right now can imagine that it is all a walk in the park. Of course it is not. The way you balance the obstacles and the opportunities has a significant bearing on how your company responds. I am overwhelmed by the positive attitude and the sheer grit and determination – of many with whom I interact – to succeed. Their success impacts on far more people in our economy than on their employees alone.

Ian Jandrell Pr Eng, BSc (Eng) GDE PhD, FSAIEE SMIEEE

The reality is – you cannot retain everyone – but the movement of the skills back into the pool can only be a positive thing for the economy.

A common thread in the discussions with really successful companies is that they are committed to investing in training – for everyone. I like that.

Editor: Wendy Izgorsek Design & Layout: Adél JvR Bothma Advertising Managers: Helen Couvaras and Heidi Jandrell

Electricity+Control is supported by:

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Quarter 1 (January - March 2017) Total print circulation: 4 702

June ‘17 Electricity+Control

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CONTENTS

16

24

34

40

Pressure + level measurement 4 Utilising Fluctuating Off-gases – With Less Flaring Philip Venter, Fanie Terblanche and Martin van Eck, University of the North-West 8 Round UP

Cables + accessories 16

Basic Principles – Trace and Locate Cables Fluke Corporation

18

Round UP

Control systems + automation 24

Globalised M2M and IoT Connectivity EMnify Team

29 30

IoT: Data and Devices for a Brave New World Sean Laval, Comsol Networks

Round UP

Electrical protection + safety 34

Safe Live Working: Complete Protection Against Arc Faults Alexis Barwise, DEHN Africa

36 39

Circuit Breaker Selection Wynand Visser, CBi-electric, low-voltage

Round UP

Plant maintenance, test + measurement 40

Aluminium Offers Benefits in Transformer Windings ZEST WEG Group

42 44

Maintenance Routing - Thermography Fluke Corporation

Round UP

Regulars

Cover

1 Comment 9 Cover Article 46 Light+Current 47 Social Engineers 48 Clipboard

SMC Pneumatics has embraced the development of electric actua- tors and now has one of the most impressive ranges of electric drive and control ranges around. Read more on page 9.

Visit our innovative online technical resource for the engineering industry. www.eandcspoton.co.za

FEATURES: • Pressure+ levelmeasurement • Cables+ accessories

• Control systems+ automation • Electrical protection+ safety • Plantmaintenance, test+measurement

EC June2017 cover.indd 1 www.electricityandcontrolmagazine.co.za 5/16/2017 10:20:25PM

Electricity+Control June ‘17

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Utilising Fluctuating Off-Gases With Less Flaring

Philip Venter, Fanie Terblanche, Martin van Eldik, University of the North-West

For an engineering plant to stay competitive, day-to-day operations must be continuously improved. These improvements may range from procuring more energy efficient plant equipment to addressing operational procedures [1].

I n process engineering plants, various by-products are being formed throughout the production chain… delivering a number of end products. These by-products should be utilised fully to generate maximum revenue. If a by-product is in a gaseous form and possesses the ability to combust in an oxygen enriched environment, it is known as a burnable off-gas and will be utilised by the engineer- ing works as an energy resource. For all further reference, mention of an off-gas will imply a burnable off-gas. Common engineering practice is to generate steam, in boiler houses, from off-gases that are not used in any of the works’ produc- tion processes. These are referred to as residual off-gases. Off-gas productions and the utilisation thereof forms part of a continuous production process and thus all residual off-gases not utilised in the boiler houses are flared into the atmosphere, wasting all of the energy potential. However, a certain flow quantity or percentage of these off-gases must always be flared to help with regulation of the off-gas pipeline pressures, since the pipelines are open to atmosphere. Pres- sure control is needed to prevent any air from entering the pipeline. If air does enter and mix with the off-gases, an extremely hazardous condition may arise. Steam is utilised all over the engineering works for various pro- duction and process heating purposes. The steam usage demands must be met at all times. Only after addressing these demands may the excess available steam be utilised by the power generating steam turbines. High temperature and pressure from the steam allows en- ergy to be withdrawn by a rotating turbine rotor. The turbine rotor is coupled to a generator that converts the rotational energy into electricity. Generating electricity, or power generation, under such circumstances is also known as power co-generation. A chemical process plant may experience non-uniformities in chemical compositions of raw materials that enter the works or even mass flow quantities that are not constant. These nonconformities may result in production quantity or quality changes over time. One result may be fluctuating of-gases and therefore steam flow produc- tions. Furthermore, steam flow demands for plant usage purposes are also not constant. This will contribute evenmore to the fluctuating steam availability for power co-generation. Irregular steamflow to the turbines will cause alternating power generation andmay result in low steam availability at times that can cause turbines to trip. If a turbine

trips, steam availability must stabilise before it may be restarted. This stabilising period is some continuous time interval where sufficient steam must be present to keep the turbine operational. The basic layout of the engineering works under consideration which produces off-gases, steam from residual off-gases and ultimately generate electricity through steam turbines is given in Figure 1 . A mathematical model was formulated in [2] to address optimal power co-generation and [3] demonstrated the applicability of this model. It was further investigated by [3] how power co-generation at this engineering plant could improve if the optimisation model from [2], rather than the plant’s operational philosophy, was used. This article investigates the additional energy potential that a power co-generation plant may potentially utilise from residual off-gases being flared. Since power generation is not the core business of this engineering works, focus is mainly placed on delivering end-products and flaring percentages were never investigated and believed by management to be regulated at 10% of the total off-gas flow. To demonstrate the potential influence on power co-generation the mathematical model from [2] will be used for various scenario simulations.

Fluctuating raw material feeds to the works

Plant processes producing off-gases

Plant processes

Plant off-gas usages

Producing steam in boiler houses

Flaring off-gases

Power generation through steam turbines

Plant steam usages

Figure 1: A basic generic layout for the engineering works.

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stant lines represent the minimum and maximum allowable steam flow limit of the turbine. All steam flow above the maximum limit (30 ton/h) cannot be utilised by the turbine and for every instance that the steam flow drops below the minimum limit of 10 ton/h, the turbine will trip if in operation. It should be noted that when power co-generation takes place in such fluctuating steam flow conditions, protection measures are in place to protect a turbine from tripping in close proximity. Common engineering practice is to allow for a time of steam stability, i.e. a continuous time interval before start-up where steam flow must be sufficient to have kept the turbine opera- tional. Under such protectionmeasures Figure 3 does not necessarily imply that six turbine trips would have been experienced within the 100 hour time period. Note that when a turbine is not operational, all power generation capability of the steam goes to waste, since it cannot be stored and utilised at a later stage. Under fluctuating steam availability steam shortages are ex- pected, however, trips should be limited as far as possible, since a turbine is designed to operate continuously and each trip occurrence depletes the life expectancy of the machine. The scenario as depicted in Figures 2 and 3 displays a situation where plant steam usages cannot be altered to assist turbines dur- ing low steam flow availability. The generic layout given in Figure 1 shows that parallel to off-gas steam production in boiler houses, off-gas flaring takes place. Thus, if plant steam usages cannot adapt to assist power co-generation, an investigation into off-gas flaring might prove to be advantageous.

Engineering considerations For the engineering plant under consideration the main focus for steam production is to ensure that plant process steam demands are satisfied and excess steam available for power co-generation is an additional advantage. Sufficient steam productions are therefore not measured in terms of available steamfor power generation. In a fluctuatingoff-gas pro- duction environment that results in fluctuating steam flow productions, it is to be expected that steam availability for power generation will not be constant and steam shortages will occur that may lead to unforeseen turbine trips. It should be noted that a turbine is designed to operate withinmaximumandminimumallowable steamflow limits. Steamflow above the maximum capacity is not allowed and cannot be utilised by the turbine. However, when the steam flow drops below the minimum allowable limit, protectionmeasureswill immediately shut down the inlet steamvalves to the turbine tripping themachine instantly. Theminimum steam flow limit helps to protect a turbine against damaging vibrations. Figure 2 demonstrates hypothetical steam flow productions from fluctuating off-gases over an arbitrary 100 hours’ time interval, where the fluctuating curve represents steam flow production (m. total ) in the boiler houses and the constant 50 ton/h line denotes plant usage (m. usage ) demands that need to be satisfied. The area between the two curves denotes excess steam available for power co-generation. As mentioned, plant steam demands are not constant and only chosen as such for illustrative purposes. If all of the excess steam from Figure 2 are utilised for power co-generation, the maximum average rate of power co-generation can be calculated by integrating the product of the area between the two curves with a conversion factor (C f ) and given by (1). This conversion factor is a function of the isentropic efficiency of the turbine, which in turn is a function of the steam flow. Some investment questions need to be addressed regarding the quantity of turbines and at what capacities need to be procured for power generation purposes. As mentioned above, this article does not address any investment questions and will only demonstrate the potential power co-generation effect if off-gas flaring is regulated.

120

100

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Excess steam (ton/h)

0

∫ 100 0

0 2 0 4 0 6 0 8 0 1 0 0

W

= ▒〖

C ƒ

(m •

– m •

)dh〗

(1)

Time (h)

max

total

usage

Figure 3: Hypothetical steam flow available for power co-generation over time, with turbine operating limits.

120

100

The following section displays simulation results for the engineering plant where co-generation exists under conditions described in this section. Measured steam productions and plant usages are used to display power co-generation capabilities. An investigation is then launched into the off-gas quantities that were flared, from obtained measurements, and how the regulation of this flaring could poten- tially have impacted power generation at this plant. As mentioned, power co-generation is only selected to stipulate the effect of off-gas flaring and therefore simulations where boiler house capabilities are hypothetically increased to observe an even more positive power co-generation effect will not be discussed. All simulations are per- formed with the optimisation model from [2].

80

60

40

20

0

0 2 0 4 0 6 0 8 0 1 0 0

Total steam production (ton/h)

Time (h)

Figure 2: Hypothetical steam flow production over time.

The hypothetical residual steam from Figure 2 is taken and plotted in Figure 3 with the addition of a turbine’s operating limits. The two con-

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Table I: Relevant turbine information. Turbine number Maximum Steam Limit [ton/h]

Figure 5: Simulated power co-generation for 10,0 MW under initial available steam flow. 8 6 4 2 0 0 500 1000 1500 2000 2500 Power generation (MW) Time (h) Investigating the flaring of off-gases Flared off-gas measurements were obtained for the time period and the total potential flared steam were calculated and plotted in Fig- ure 7 . When Figure 7 is compared with Figure 4 it can be seen that a significant amount of potential steam is flared into the atmosphere where the energy potential is wasted. Calculations showed that 55,2% of all energy potential in the residual off-gases were flared, resulting in only 44,8% usage of this energy resource. The 55,2% correlates to a 46,9% combined off-gas volume flow that was flared. Take note that the low off-gas flaring instances correspond to

Minimum Steam Limit [ton/h]]

Conversion Factor C ƒ

T T

(10,0 MW) (25,0 MW)

55,0

16,5 33,0

10/55 10/55

1

137,5

2

Simulation results A number of simulations were performed on the power co-generation capabilities of the engineering plant that utilises residual off-gas for steam productions. The aim was not to simulate what capacity size turbine or combination thereof will yield the best power genera- tion, but to demonstrate the effect that off-gas flaring control could potentially have on the outcome of a plant’s power co-generation. The excess steam that was available by the plant during the time of investigation is plotted in Figure 4. Fluctuations with low steam flow intervals are clearly evident in Figure 4. To determine the total power generation potential if all of the steam could be utilised, (1) is used. All the relevant turbine information used for the simulations can be found in Table 1 , i.e. turbine capacities, steam flow limits and

the conversion factor. For simplicity the conversion factor is chosen to be equal for both turbines and constant for all of the operating points. The first set of power co-generation results are that of the plant for the initial steam flow profile that will be used as basis for comparison purposes.

low steam flow production occurrences and even if all available off-gases were to be used to generate steam, low steam availability periods would still have existed. However, even though it is evident from Figure 7 and these percentages that significant quantities of potential steam generation does not take place, it is not yet possible to comment on how this could potentially affect the power co-generation.

250

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150

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0

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2500

0 500 1000 1500 2000

5

Time (h)

Power generation (MW)

0

Figure 4: Available steam flow for power co-generation.

0 500 1000 1500 2000 2500

Time (h)

Figure 6: Simulated power co-generation for 25,0 MW under initial available steam flow.

Simulations for initial available steam flow The numerical integral was determined for the initial steam flow as depicted in Figure 4 and the maximum average rate of power co- generation was calculated at . W max = 21,4 MW. The combined power co-generation from turbines T 1 and T 2 equals 35,0 MW and will be used for all steamflow scenario simulations with the combined boiler houses’ capacity of 260 ton/h. Power co-generation results obtained for T 1 and T 2 are plotted in Figures 5 and 6 respectively. Turbine trips due to steam shortages are evident in these two figures and, further- more, that both T 1 and T 2 operate mostly below the maximum limits. T 1 only operates at maximum capacity for 5,1% and T 2 for 21,7% of the time. The total combined average rate of power co-generation is 20,5 MW out of a potential of 21,4 MW and simulation results show 18 combined trips for the turbines during the time period.

In order to investigate how power co-generation could have been improved due to less off-gas flaring, the potential steam that could have realistically been generated must be calculated, i.e. taking into account the total steam generated as well as the combined boiler houses’ capacity. The potential steam that could additionally have been generated during this time can be seen in Figure 8. Figures 7 and 8 have been plotted on the same y-axis intervals to demonstrate the difference between the potential steam flow that was flared against the maximum additional steam flow that could potentially have been produced. These plotted results further indicate that significant steam flow productions cannot take place due to boiler house capacity restrictions.

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350 300 250 200 150 100 50 0

number of combined turbine trips. Even though sufficient steam is mostly available to operate both turbines at maximum capacity, turbine trips cannot be eliminated, due to instances of low off-gas productions as seen in Figure 7. In Table 3 the time percentages are displayed for both T 1 and T 2 , for all of the different steam flow scenarios, where power co-gener- ation occurs at maximum capacity and for when the turbines are in trip. The results show, as expected, that when the flaring percentage reduces, turbines will operate more frequently at maximum capac- ity with less time in a tripped state. The reported values in Tables 2 3 do not show significant changes when the flaring percentage is lowered from 10,0% to 5,0%. The conclusion to be drawn is not that there exists a flare percentage where after improved flaring control does not increase energy utilisation, but that the combined boiler houses’ capacity is the limiting factor. This correlates with what was seen in Figures 7 and 8. Table 3: Time percentages for turbines operating at full capacity or be- ing in trip. Time % for Maximum Operating Capacity Time % for Turbine in Trip Taking this information into account, it will make sense to simulate scenarios where the combined boiler houses’ capacity is increased to further investigate the effect on power co-generation for this engineering plant. With an increase in steam production capabilities additional tur- bines will have to be added for the simulation model or the operating limits of T 1 and T 2 should be increased. Conclusion An engineering works that produces and utilises fluctuating burn- able off-gases during normal plant operations was investigated. The residual off-gases that are not used for plant process purposes are used to generate steam, in boiler houses, and the remaining off- gases are flared to atmosphere, nullifying the energy potential. Steam flow productions are necessary for a variety of plant processes and these usages may fluctuate over time. Once all plant steam demands are met, excess available steam is utilised for power co-generation through the use of steam turbines. References [1] E. Vine (2008). Breaking down the silos: the integration of energy efficiency, renewable energy, demand response and climate change. Energy Efficiency 1, pp 49 – 63. Flare % T1 T3 T1 T3 46,9 40,0 30,0 20,0 10,0 5,1 21,7 38,4 63,4 78,0 82,7 84,4 20,0 15,2 14,0 17,0 15,1 18,0 37,0 52,4 60,2 62,0 7,7 8,2 7,0 8,2 9,7 6,4 3,7 5,0

350 300 250 200 150 100 50 0 Steam flow (ton/h) Steam flow (ton/h)

0 500 1000 1500 2000 2500

Time (h)

Figure 7: Total potential steam productions flared to atmosphere.

As mentioned, the boiler houses consist of a maximum steamproduc- tion capacity of 260 ton/h. Furthermore, for line pressure control to ensure that air does not enter the off-gas pipelines, which are open to atmosphere, a certain quantity must always be flared. It is therefore never possible to utilise all the energy potential from the off-gases.

0 500 1000 1500 2000 2500

Time (h)

Figure 8: Potential steam productions flared to atmosphere that could have been realised.

Influence of regulating off-gas flaring percentage It was mentioned earlier that management was under the impres- sion that off-gas flaring was regulated to be 10% of the volume flow, whereas in the previous section it was reported that on a volume basis 46,9% of the off-gases were flared. Five different off-gas flaring scenarios are chosen that range from 40,0% down to an optimistic 5,0%. For each scenario the potential steam that could have been avail- able are calculated and simulations are performed by means of the mathematical model. The power co-generations are given in Table 2 .

Table 2: Turbine simulation results for various off-gas flaring percentages.

Max Potential Power Generation [MW]

Combined Power Generation [MW]

Flare %

Trips

46,9 40,0 30,0 20,0 10,0

21,4 25,2 30,1 33,4 35,0 35,5

20,5 23,1 27,0 29,7 30,8 31,4

18 25 20 15 13 11

5,0

From the results in Table 2 it can be seen that if off-gas flaring was controlled, significant increases in power co-generation could poten- tially have taken place. Allowing for only 10,0% of flaring, the potential power co-generation could increase with up to 50,0% with a reduced

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• Researchers investigate what happens when volume quantity of off-gas flaring is regulated and the improved potential that this could have on power co-generation. • Steam is generated, in boiler houses, from burnable off-gases that are not used in the works’ production processes. • A certain percentage of these off-gases must be flared to help with regulation of the off-gas pipeline pressures since the pipelines are open to atmosphere.

[2] P.v.Z. Venter PvZ, S.E. Terblanche & M. van Eldik. (2015). Off- gas power generation optimization using a mixed integer linear programming model. ORSSA 2015 pp 81-90. [3] P.v.Z. Venter PvZ, S.E. Terblanche &M. van Eldik. (2015). Improv- ing Power Generation fromFluctuating Off-Gas Productions. ICUE 2015 pp 225-231. [4] H. Lund. (2007). Renewable energy strategies for sustainable development. Energy 32, pp. 912 – 919. [5] Z. Beihong & L Weiding. (2006). An optimal sizing method for cogeneration plants. Energy and Buildings 38, pp. 189-195. [6] J.M. Carrasco, J.T. Bialasiewicz, R.C.P. Guisado & J.I. Leon. (2006). Power-Electronic systems for the grid integration of renewable energy sources: a survey. IEEE transactions on industrial electron- ics 53(4). [7] S. Fazlollahi, P. Mandel, G Becker & F. Marechal. (2012). Methods for multi-objective investment and operating of complex energy systems. Energy 45, pp. 12-22. [8] S. Fazlollahi & F. Marechal. (2013). Multi-objective, multi-period optimization of biomass conversion technologies using evolution- ary algorithms and mixed integer linear programming (MILP). Applied Thermal Engineering 50, pp. 1504-1513. [9] M. Poschl, S. Ward & P. Owende. (2010). Evaluation of energy efficiency of various biogas production and utilization pathways. Applied Energy. 87, pp 3305-3321. [10]I. Dincer. (2000). Renewable energy and sustainable development: a crucial review. Renewable & Sustainable Energy Reviews 4, pp 157-175.

take note

Philip Venter is a mathematical and statistical optimisation engineer, employed at the School for Mechanical and Nuclear Engineering at the NWU and a part-time Ph.D. student at the Centre for Business Mathematics and Informatics (BMI) at the NWU in Operations Research. Professor Fanie Terblanche is employed as an associated profes- sor at the Centre for Business Mathematics and Informatics. His main research interests are the formulation of optimisation models and the development of appropriate algorithms to gener- ate solutions for these models. Professor Martin van Eldik is an associate professor in the School of Mechanical and Nuclear Engineering where his research group focuses on the next generation of heat pumps including the use of CO 2 as refrigerant for high temperature applications.

Enquiries: Philip Venter. Email 12330825@nwu.ac.za

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Portable differential pressure measurement with internal sensor

Kobold, represented locally by Instrotech , has on offer their highly precise pressure measuring devices HND-P121/P231 to HND- P127, with integrated pressure sensors. On the top of the housing they have two pres- suremeasurement inputs that are connected to themeasuring points bymeans of a stable metal connection and plastic hoses, avail- able as accessories. Numerous measuring ranges in the over- pressure and under-pressure range are avail- able for various measurement tasks, such as differential pressure measurement. In addition to pressure display, these first-rate, compact, universally applicable measur- ing units offer additional functions such as minimum/maximum value memory, a hold function, tare function, automatic self-shut- off, or zero point offset.

The devices with an expanded spectrum of functions also have a logger function, a peak value memory, minimum/ maximum alarm, an adjustable measuring cycle, and averaging. Key features: • Integrated pressure sensor • Differential pressure measurement • T hose connections • Serial interface • Extensive additional functions • Relative pressure sensors Areas of application are chemical, pharma- ceutical and food industries; machine and apparatus construction as well as piping and container construction. Enquiries: Instrotech.Tel. +27 (0) 10 595 1831 or email sales@instrotech.co.za

Electricity+Control June ‘17

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COVER ARTICLE

OEMs and end users − Can you afford not to GO ELECTRIC?

FEATURES: • Pressure+ levelmeasurement • Cables+ accessories

• Control systems+ automation • Electrical protection+ safety • Plantmaintenance, test+measurement

SMC Pneumatics looks into the benefits of specifying electric actuators

EC June2017 cover.indd 1

5/16/2017 10:20:25PM

I t is generally accepted that electric actuators provide flexibility plus precise control in terms of position control, speed control, torque control and variable acceleration and deceleration, when compared to the use of standard pneumatic actuators.Whilst falling energy charges have helped address some of the cost issues when using compressed air, high maintenance and operating expenses still remain a major factor. Electric actuators are particularly suitable when used in medium sized applications. Their flexibility of performance, coupled with their excellent energy efficiency and lower maintenance and replacements costs can be enjoyed, without the high generation and maintenance costs associated with compressed air systems. In reality, the power draw of the motor is largely responsible for the operating costs as the low voltage circuitry in the amplifier and the controller consume minimal amounts of energy.The largest costs in manufacturing applications today are usually down to changes or adaptions to an assembly line to accommodate a different product – manual changeovers. These can be incredibly expensive in terms of lost production and engineering time to make these changes. However, because electric actuators are programmable, changeover costs can be dramatically reduced. When you consider the efficiency gained during changeover activi- ties, plus the added energy efficiency when using electric actuators, the higher initial component costs are soon negated. SMC, which is traditionally recognised as the world leaders in pneumatic technol- ogy, has embraced the development of electric actuators and now has one of the most impressive ranges of electric drive and control ranges around.

SMC’s latest catalogue of electric actuators and controllers has over 900 pages of product information to help you select the right solution. Today it can offer customers simple, easy to programme and easy to use controllers for the majority of the electric actuator range or technically advanced high performance Series LEY, LEYG, LEF and LEJ options for use in more demanding applications. Additionally, if you have a well-established motor and control philosophy then why not take advantage of SMC’s motor-less option? As standard, these actuators can be specified to match a comprehensive list of over 14 motor manufacturers. “Today, we have a range of electric actuators to meet virtually any need and our controller range has expanded accordingly,” confirmed Ernst Smith, Product Manager at SMC Pneumatics SouthAfrica. “Over the past fewmonths we have been promoting the fact the SMC ismore than just pneumatics and when customers see our new electric actua- tor catalogue they will find everything they will need to go electric.”

Enquiries SMC South Africa

Tel: +27 (0) 11 100 5866 Email: sales@smcpneumatics.co.za

June ‘17 Electricity+Control

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PRESSURE + LEVEL MEASUREMENT

HOT topic in beverage production

Today nearly every liquid sold in stores is pasteurised to prevent the growth of bacteria and the potential for illness due to these unwanted microorganisms. Milk is one of the most susceptible liquids to this and only pasteurised milk is considered safe by the FDA. Pasteurisation of milk results in at least 95 - 99% of the bacteria and micro-organisms present (pathogenic germs) being destroyed.

heat exchanger 1, the rawmilk is pre-heated to approximately 55°C. It is then fed to the separator and homogeniser, and then proceeds into heat exchanger 3, where it is heated to the pasteurisation temperature (>72°C). In the heat retaining sec- tion, the milk is kept hot at the corresponding temperature for the required time, forcing it to flow at a constant rate through a given pipe length. Heat treatment time is determined by

flow velocity and the pipe length. An electromagnetic flow meter is well suited to precisely measure the flow rate of the milk.The Promag H is a multivari- able measurement for flow, measuring volume flow, temperature, conductivity, mass flow, corrected volume flow and corrected conductivity. The innovative HeartbeatTechnology also allows online verifications to be done on demand as often as needed. The Pt100 temperature sensor (T1) and valve 1, control the heat exchanger temperature. The Pt 100 sensor (T2) at the outlet of the heat exchanging section also monitors the temperature in order to ensure that the required temperature prevails in the entire the heating section. If the heat exchanger temperature falls below the required temperature, then safety valve 3 switches and directs the incorrectly treated milk into a circuit or back into the pre-settling tank.The tem- perature measurement and control is of

Raw milk is passed from the accumulation tank into the pre- settling tank. To maintain constant pressure on the suction side of the pump, the milk is kept above a minimum level in the pre-settling tank. By means of level switches and valves, the fill level is

extreme importance and has a direct impact on the taste and quality of the milk. A lower temperature can result in the risk of microbiological contamination and therefore a risk to the consumers’ health. Specially designed for use in hygienic ap- plications within the Food & Beverage industry, the iTHERM QuickSens is the fastest temperature sensor in the world, with the quickest response times (t90s: 1,5 s). Once the milk has been pasteurised, it is passed to the heat exchangers 1 and 2, where it is cooled down to 4°C. An electronic differential pressure transmitter can be used to calculate the differential pressure. The Deltabar FMD72, eliminates the typical problems of conventional differential pressure systems.The problems most frequently associated with oil-filled capillaries are; unreliable measured values due to temperature changes, leaks or condensate. The FMD72 provides precise measurement and also facilitates reliable and safe process control. The differential pressure, with the temperatures and flow rates, can be recorded on a data acquisition system. The advanced Memograph M is a flexible and powerful system for organising process values and allows perfect monitoring and registration of all the process parameters in a glance. The measured process values are clearly presented on the display and logged safely, monitored against limit values, and analysed. Enquiries: Natlee Chetty. Email natlee.chetty@endress.com

maintained as to pre- vent any air intake. The

Liquipoint FTW33 uses a new sensor technology offering the advantages of reliability and automatic build-up compensation, even in the pres- ence of foam or bubbles. No onsite calibration is required and the unit is installed without the need for any special tools. If, during heat treatment, the product flow needs to be recycled (where heating is made inadequate or if contamination is present in the heat exchanger), the milk is often fed into the pre-settling tank, forcing the product to flow in a closed circuit until the error is rectified. From the pre-settling tank, the milk is passed into the pasteuriser. In

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PRESSURE + LEVEL MEASUREMENT

Pneumatic test pump kit

Fluke Calibration , represented locally by Comtest , has introduced the 700HPPK Pneumatic Test Pump Kit, a rugged, portable tool that generates and adjusts pneumatic pressures up to 21 MPa (3 000 pounds-per-square-inch) without requiring a nitrogen bottle or other external pressure supplies. It is ideal for generating high pressure in the field to Devices Under Test (DUTs), such as transmitters, controllers, pilots, and analogue gauges. The 700HPPK reaches pressure in 20 seconds to full scale into a 30 cm 3 vol- ume. A detachable pressure adjustment system and adjustment control knob al- lows technicians to make fine pressure adjustments to 0,05% of reading or better. The lightweight and portable pneumatic pressure kit is designed for use in the lab or the field with collapsible feet, a built- in handhold, and a canvas carrying case making it field-portable. In-line filter and desiccant systems pro- tect the device against con¬tamination from the DUT, and it works on almost any

surface, so technicians do not need a flat laboratory bench or flat area in the field.

The 700HPPK has the versatility to cover a wide range of workloads. It features a 2-meter pressure line and assorted pres- sure fittings to connect to a variety of DUTs for wide workload coverage. Its ¼ NPT female reference gauge connector fa-

cilitates easy reference gauge switching. No PTFE tape or extra tools are required, reducing the equipment and accessories techni- cians need to carry to the job site. The calibration manifold attaches and de- taches smoothly via quick detent pins that reduce set up and pack up time. A second model, the 700HPP, is available specifically for high pressure source users. Enquiries: Tel. +27 (0) 10 595 1821 or email sales@comtest.co.za

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PRESSURE + LEVEL MEASUREMENT

New compact transmitter for control cabinet installation

Knick Elektronische Messgeräte has expanded its slender Memosens transmitter series MemoRail for control cabinet installation with a Modbus interface version:The MemoRail Modbus A1405N is the first multi-parameter analysis device that provides process technol-ogy operators with an eco- nomic, compact transmitter for full-featured integration of Memosens monitoring stations into the fieldbus standard. Up until now, only comprehensively equipped analysis devices with a display, or compact solutions with limited functionality, were available on the market for this purpose. The new MemoRail Modbus modules from Knick, which feature a modular housing with a width of just 17,5 mm, only transmit all sensor data and readings to the Modbus master using the MODBUS RTU data format. Unlike conventional compact solutions, they also enable unrestricted access to device configuration and sensor calibration via Modbus. Up to 32 transmitters can be connected to a Modbus master. For the measurement of pH/redox, conductivity or oxygen, MemoRail Modbus can be combined with all Memosens and digital sensors whether pH glass, IsFET, oxygen, or conduc- tivity (conductive and inductive). What's more, the DIN rail module is the only analysis device of its class that enables the connection of LDO sensors (luminescent dissolved oxygen) for the optical measurement of oxygen.The new devices are available in one and two-channel versions with freely combin- able parameters or sensors. Either two freely selectable

Memosens sensors or Memosens sensor and an SE 740 LDO can be connected. Additionally, the transmitters allow for the connection of the new SE 554 X/1-AMSN and SE 555 X/1-AMSN combination sensors that synchronously de- termine pH and redox value respectively. In this way, a two-channel MemoRail model pro- vides four readings as well as temperature.

The network address for rapid MODBUS configuration is set via DIP switch on the front panel. The 24 Vdc supply can be connected either viaTBUS or via a cable connected to the terminals at the back. Red and green LEDs indicate the status, communication interruptions, defective sensors or device settings unsuitable to the sensor as well as the device's main- tenance requirements. Knick provides a three year warranty on the MemoRail-Modbus transmitters. Mecosa is the sole agent for Knick Elektronische Messgeräte in Southern Africa. Enquiries: +27 (0) 11 257 6100 or email measure@mecosa.co.za

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PRESSURE + LEVEL MEASUREMENT

Reduce downtime, improve reliability with separated valve SMC recently introduced a new 2/3 Port media separated LVMK20/200 valve series to its collection of over 12 000 basic products.The valve has been designed to prevent armature sticking and corrosion that in the past has led to equipment or valve failure. Brian Abbott, Product Manager at SMC Pneumatics, ex- plains that by preventing fluid from entering the solenoid assembly, it remains pollution free from oil, metal and dust particles, improving overall performance and reliability. “As a result of this, the launch of a new 2 and 3 port media separated valve means improved performance and lowered component costs”. Designed for sensitive applications such as water purifica- tion and blood and atmospheric pollution analysers, thanks to its media separation structure, the LVMK20/200 series has proved popular overseas. “There are two models to choose from, either a base mounted or body ported option, offering customers flexibility in terms of use.The body portedmodel features an integrated barb fitting, allowing for easy piping which delivers labour savings,” explains Abbott. Both designs are easy to clean, as there is very little dead space, reducing cleaning costs and eliminating the need to adjust flow rates with the 3 port valve, keeping leakage rates to a minimum. Enquiries: Email kmccarthy@smcpneumatics.co.za or visit www.smcpneumatics.co.za

Brian Abbott, SMC Pneumatics.

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PRESSURE + LEVEL MEASUREMENT

Very ‘smart’ smart water metering solutions The accuracy and broad range of Kamstrup’s smart water meter- ing solutions are attracting significant interest frommunicipali- ties, utilities, and environmental agencies in South Africa. The company has continuously nurtured and enhanced the value of its products to offer customers advanced solutions for a low total cost of ownership. Kamstrup’s smart water metering solutions combine the newest ultrasonic technology with remote reading, advanced pressure, and leakage surveillance to allow utilities to control their water distribution systems in previously impossible ways. The improved solution helps users monitor temperature, pres- sure, water quality, and water loss in the distribution network. The superior data quality, consistency, and remote system configuration capability go a long way in helping utilities make real-time decisions and optimise operations. Additionally, the most outstanding feature of Kamstrup’s meters is their ability to retrieve data with the help of drive-by, walk-by or fixed infrastructure technology.The technology nei- ther relies on end users to read the meter, nor requires them to send the consumption data.When utilities need to collect meter data, they merely have to drive near the meter’s location. The data is automatically collected and transferred to the meter data management system. The data collected from Kamstrup’s systems are more com- prehensive than the data from any other type of meter. It con- tains information about leaks and bursts, as well as the highest water flow rates, enabling customers to understand their water consumption levels and patterns and prepare for the future. Kamstrup’s two modular, multi-communication smart water meters − the MULTICAL 21 and flowIQ 3100 − are aimed at the residential and industrial segments, respectively. Kamstrup’s meters maintain high precision throughout their lifetimes, even if the flowrate falls. Furthermore, its meters were tested and approved by the South African Bureau of Standards (SABS) in 2013, resulting in huge boost to saleability. Enquiries:Tel. +27 (0) 87 357 8659 or visit www.kamstrup.com

Fast and accurate automatic pressure testing Fluke , represented locally by Comtest , has just launched the new Fluke 729 Automatic Pressure Cali- brator, simplifying the calibration process by automat- ing pumping to the precise test pressure, improving calibration integrity by compensating for minor leaks, and automatically documenting the pressure calibra- tion process. With the rugged, portable 729, technicians simply input a target pressure and the calibrator automati- cally pumps to the desired set-point while the internal fine adjustment control stabilises the pressure at the requested value. Fluke 729 features • Automatic pressure generation and control for multiple tests to 300 psi, (20 bar, 2 MPa). Fill in a test template and the 729 automatically pumps to and documents a multiple-point pressure calibra- tion test • Easy calibration documentation using defined templates for transmitters and switches. Input the starting and ending test pressures and number of test points and the calibrator documents the applied pressure, measured mA, and percentage error for each test point. The bright colour graphi- cal display flags out of tolerance test results in red • HART communication enabling mA output trim, trim to applied values, and pressure zero trim- ming of HART pressure transmitters. Technicians can also perform light configuration tasks such as changing a transmitter tag, measurement units, and ranging • Measurement of mA signals on transmitter outputs and sourcing and simulation of mA signals for testing IPs and other mA loop devices. It includes a 24 V loop power supply for testing and powering transmitters in standalone tests disconnected from the control system Enquiries:Tel. +27 (0) 10 595 1821 or email sales@comtest.co.za

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Direct and accurate measurement of level in bypass chamber With OPTIWAVE 1010, KROHNE has introduced a new radar level transmitter for bypass chambers and magnetic level indicators. The 2-wire FMCW radar level transmitter is designed as a cost- effective solution for the continuous level measurement of liquids in bypass applications in various industries, e.g. chemical, power, water and wastewater, or automotive. OPTIWAVE 1010 can be combined with the KROHNE BM 26 ADVANCED bypass chambers and magnetic level indicators (MLI), thereby adding a 4…20 mA HART output to the mechani- cal devices. The combinations can be conveniently ordered as a whole, e.g. as BM 26 W1010 (OPTIWAVE 1010 welded to BM 26ADVANCED). Alternatively, it can be welded on any bypass chamber with internal diameter 38…56 mm / 1,5…2,2".Thus it is also an ideal solution for other MLI manufacturers to add a level radar measurement option to their product range. OPTIWAVE 1010 is competitively priced to replace reed chains, magnetostrictive and simpleTDR transmitters that are typically used with bypass chambers or MLIs. In addition to a measuring accuracy of ±5 mm / 0,2", the FMCW principle offers a much better overall accuracy in bypass applications: while reed chain and magnetostrictive principles are measuring the float position which depends on the product density, the FMCW radar directly measures the liquid surface. Application range for OPTIWAVE 1010 includes almost any liquids with process temperatures ≤ +150°C / +302°F up to 40 barg/ 580 psig and measuring ranges up to 8 m/ 26,2 ft. With clean liquids of dielectric constant e r ≥ 3 the device measures the surface directly, for e r < 3, a float with target is used. OPTIWAVE 1010 features a dual process seal system that al- lows for removal of the converter under process conditions.The 2-wire loop-powered HART device is pre-configured in the factory and delivered ready to use. Application-specific adjustments are possible via HART/ DD and DTM. Enquiries: Clayton Duckworth.Tel. +27 (0) 11 314 1391 or email C.Duckworth@KROHNE.com

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CABLES + ACCESSORIES

Basic principles Trace and Locate Cables Fluke Corporation

This cable locator, with a digital coded transmitter signal, ensures that the signal is clearly received by the transmitter.

The Fluke 2042 cable locator.

M any electrical professionals have the need to trace cabling or wiring systems. This can often be a tiresome and time con- suming practice. In addition, there is often the requirement to identify which safety devices are connected to certain circuits or the need to identify and trace metallic conduit, heating pipes or under- ground cabling. The new cable locator has been specifically designed as a multi-purpose tool to assist the user in all of these applications. The FLUKE-2042 cable locator consists of a transmitter and a receiver. The transmitter supplies a modulated alternating voltage to the cable concerned which generates an electrical field around the cable. The receiver is fitted with a coil and is placed in close proximity to the electrical conductor, the lines of flux will run through the coil and into the receiver. A small amount of voltage is produced in the coil, which is measured by the electronics of the receiver and is shown on the display.The special feature of this cable locator is the digital coded transmitter signal. This ensures that the signal is clearly received by the transmitter. Incorrect displays caused by any interfering fields e.g. from electronic fluorescent lamp ballasts or frequency converters are avoided (see Figure 2 ). In general, there are two different application principles, with and without voltage. Application without voltage A typical application is locating switch and distribution boxes that have been inadvertently covered over with plaster or accidentally concealed within the building fabric. Almost everyone is familiar with the scenario: The switch and distribution boxes are set and the cables are laid out for a new installation. After the walls have been covered, not all of the sockets can be located. In this case, it is sufficient to

Application with live voltage It is a frequent occurrence that electric circuits in old systems are not labelled. To avoid interrupting an incorrect supply, the correct safety device must be assigned to the correct electric circuit. The cable loca- tor described can be used for this application. Connect the signal transmitter directly to the phase and neutral wire (see Figure 3 ). The signal detection strength is generally reduced with this application. The electric flux of the alternating voltage and the signal transmitter mutually affect one another. However, the re- duced tracing depth is not of significant importance in this case, as the cables are directly accessible in the opened distribution cabinet.

Figure 3: Example of application, allocation from electric circuits to safety devices without switching off the system.

Procedure for locating cables In order to be able to proceed successfully with this type of application, it is necessary to have a theoretical understanding of the operating mode. The approach is illustrated using the example of a covered socket. In this case the electrical outlets are often the only places that are accessible to the cable. Here the transmitter’s signal is fed onto this cable. The transmitter is connected as described under the application without voltage. The earthing contact of a nearby plug socket or an extension lead is used as a grounding connection. Now the run of the concealed cable is traced until the signal is no longer received. The operator can manually adjust the level of sensitivity on

supply the signal to any wire of the cable which needs to be traced. The second pole of the signal transmitter is attached to the earth potential by a ground wire. Figure 2: Operational principles of this cable locator.

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