Tag Archives: Zest WEG Group


Precision manufacturing at the WEG Blumenau factory in Brazil allowed Zest WEG to supply two large, custom-built power transformers a month ahead of deadline to a power utility strengthening the reliability of the region’s power system.

The fact that both 500MVA 400kV transformers passed the factory acceptance test (FAT) first time around paved the way to early delivery. This achievement, according to Jan-Frederik Viljoen, executive  transformers at Zest WEG, is a testament to the company’s design and manufacturing quality. 

The 348 t units are the largest yet produced by WEG – with each unit boasting a power rating of 500,000kVA and voltage class of 400kV. This delivery efficiency reinforces Zest WEG’s position in the local market.

“Our South African team participated actively in this project, reaffirming WEG’s commitment to the development of our employees and the transfer of skills,” says Viljoen. “We see this as a vital contribution to the development of the country, as well as the alleviation of the energy shortage in the region.”

He says the benefits of these transformers include robustness, flexibility and reliability – contributing directly to the development of the local economy. They are also an important element of expanded investment in emergency capacity to generate complementary power supply for the region.

Zest WEG’s manufacturing operations in South Africa include two transformer factories near Johannesburg, which produce and supply the local market with 145kV voltage class transformers. This contract is an important achievement for Zest WEG, which is deepening its contribution to power generation, transmission and distribution as part of its developmental mandate. The company is well-established in the mining and industrial sectors, and is currently raising its level of engagement with power producers and municipalities.

Zest WEG’s portfolio includes power distribution equipment such as miniature substations, distribution transformers and power transformers, as well as packaged switchgear and automation solutions such as E-Houses, Motor Control Centres (MCC) and electrical enclosures. Among its power generation solutions are conventional diesel generators, combined heat and power generation (CHP) and renewable energy generation.

Other offerings relevant to the public sector include the supply of substations and electrical infrastructure, including the design, supply and construction of overhead lines, substation mechanical and electrical construction, and electrical high-voltage and low-voltage reticulation.


When a process plant in South Africa’s Mpumalanga province needed an improved starting method for its rod mill, Zest WEG was able to supply its WEG SSW7000 medium voltage soft starter.

The plant had recently upgraded to a 450kW, 8 pole, 6600V WEG W50 motor, which was started by a direct online starter. 

According to Fritz Hoogenboezem, branch manager at Zest WEG Middelburg, the soft starter was imported into South Africa from WEG’s Brazil factory in time for the plant’s scheduled shutdown, and was installed by local systems integrator Umagezana Engineering. 

“By avoiding the sudden in-rush of current when the motor is switched on, the soft starter reduces both the mechanical stress on equipment and the peak load drawn from the national power grid,” says Hoogenboezem. 

There is a direct financial benefit to be derived by the customer if their peak consumption reduces to a lower peak demand value. This is because exceeding the maximum demand – as can occur when a large motor starts up – leads to costly penalties being applied by the power utility. The in-rush current to start a heavy-duty load can, in those first few milliseconds, be seven to ten times higher than the level at which the motor is specified. 

“By exceeding the maximum demand, the plant could pay much more than necessary for its power consumption, not just for that month but for 12 months afterwards,” he says. 

The installation of the soft starter was a complex task, according to Umagezana Engineering director Ernest Bean. Once they removed the direct online starter, it was clear that the cable lengths would not fit directly onto the new soft starter. 

“This required changes to be made with the motor control centre (MCC) on the high voltage side,” says Bean. “The different cable lengths meant that cables had to be re-terminated to ensure safe and compliant operation; nine cores or phases were terminated.”

Another challenge was that the door to move the equipment in and out was not wide enough. This required specialised rigging to be carefully planned and conducted, as the WEG SSW7000 soft starter weighs almost a tonne. 

Once the new equipment was installed and connected, Zest WEG’s qualified drives and automation technician Reiner Gundlach assisted with the cold and hot commissioning. Extensive tests were run in accordance with WEG’s detailed OEM specifications, laying the technical foundation for the optimal performance and lifespan of the equipment.

“As a sophisticated medium voltage item, there are numerous aspects that need checking and testing,” says Hoogenboezem. “The results are then communicated with WEG as part of our rigorous quality management procedures.”

Bean highlights that, as a technician in the field, he was impressed by the smart use of fibre optics between the control section and the high voltage operational side. In particular, the functionality test in the soft starter’s software is able to test each individual fibre optic cable using a control voltage of 230 volts, before the system is opened to the full 6600 volts used for operations.

“Among the other benefits of the soft starter is its monitoring functionality, which allows the plant management to closely track the interaction between the motor, the soft starter and the plant PLC,” he says. “Management can at any time log into the PLC and use that interface – together with the soft starter – to view important information such as tonnages processed, and the number and duration of stoppages.”

Umagezana Engineering was appointed by Zest WEG as a distributor for the WEG low voltage switchgear range in January 2021. Its whole team has also recently completed the required MV training for high voltage terminations and cable joints, which was done through a specialist firm accredited by the Energy and Water Sector Education Training Authority (EWSETA).


As solar energy contributes increasingly to cleaner, renewable energy for a more sustainable world, WEG has introduced its complete ESW line of central inverter stations for photovoltaic power generation plants. These are available through Zest WEG, WEG’s South African operation. 

The WEG ESW 750 centralised solar inverter stations are custom-engineered for large scale solar plants, comprising a range of WEG’s SIW 750 inverters, with a modular design to promote greater flexibility in their application. They can easily be integrated to suit the specific requirements of each solar power plant, and can withstand even the most extreme weather conditions including ambient temperatures from minus 10⁰C to plus 50⁰C.

Available in capacities up to 10MW at 1,500V, these WEG solar stations represent an integrated solution with central inverters developed and manufactured with cutting-edge technology. Their design allows for quick installation and simplified operation and maintenance. 

As one of the world’s largest manufacturers of electric motors, electronic equipment and systems, WEG has the know-how to ensure that every solar station is fit-for-purpose and assures safety, efficiency and reliability. 

Solar power has become an increasingly competitive renewable energy source around the world, and offers fast installation with low environmental impact. Developed to support this important global trend, WEG’s central inverters provide a complete solution for investors who want to take the lead in contributing to a more sustainable future.


In the face of rapidly rising electricity costs in South Africa, Zest WEG is phasing in IE4 super‑premium efficiency motors in its WEG W22 range from April 2021 – which will save on customers’ bottom lines and help reduce the load on the national grid. 

According to Fanie Steyn, electric motors manager at Zest WEG, 2021 will see local energy prices rising above R1/kWh for the first time. This makes it the ideal time for the introduction of WEG IE4-rated motors, which will be available in the size range between 37 kW and 375 kW.

“Unlike many countries around the world, South Africa has not regulated the use of energy efficient motors at the level of IE2 or IE3,” says Steyn. “Nonetheless, we have taken the proactive step of making the IE4 level of efficiency available to customers at no premium on the IE3 units.”

Some years ago, Zest WEG introduced its WEG IE3 motors to the country at little or no additional cost relative to its IE2 motors, with the same goal in mind: making both customers and the country more energy efficient.

Specified under the International Electrotechnical Commission (IEC) 60034-30-1:2014 standard, IE1 refers to standard efficiency and IE2 to high efficiency; the IE3 and IE4 ratings are for premium efficiency and super-premium efficiency motors respectively.

“The efficiency of 96.3% on an IE4-rated 110kW motor, when compared to 94.1% on an IE1-rated motor, can save users hundreds of thousands of rand in energy costs over a 10 year period,” he says. “Not only will these IE4 motors be more cost effective to run, but they have been designed with a number of new features that bring considerable benefits.”

Steyn emphasises that WEG IE4 super-premium efficiency motors meet IEC efficiency levels when running on 50 to 100% of load; efficiency is kept constant, which saves energy and ensures minimal losses through various loading points. The innovative frame design also allows maximum heat dissipation.

“Motor frame design plays a crucial role in thermal performance, as it is responsible for the outward transfer of heat generated inside the motor,” says Steyn. “Running cooler means that our motors have increased life spans, allowing Zest WEG to offer a five year guarantee on our WEG W22 electric motor range.”

The motors’ increased mechanical rigidity – achieved by integrating the front and rear feet sides – affords easier installation, higher mechanical stiffness and improved distribution of the mechanical thrust imposed by the load.

“As a first of its kind, our flexible terminal box mounting means reduced inventory and quicker modification,” he says. “The terminal box can be rotated in 90° increments to facilitate supply cable connection orientated to the front, rear, top or either side of the motor.”

In addition to the benefits brought by WEG super premium efficiency motors a substantial increase in energy savings can be reliably achieved using WEG Variable Speed Drives (VSDs), which comply with the European Extended Product standard EN50598. This ensures the system efficiency of the motor and VSD combination. As an additional feature, WEG VSDs have energy savings settings which can be user activated, achieving an automatic saving under any reduced load conditions.

“We are excited to build on the phenomenal reputation of the existing WEG W22 electric motor range by offering an even more efficient motor that is truly “next level” state of the art in electric motors, having the same rock solid quality and reliability,” Steyn concludes.


The new WEG SSW900 soft-starters are the ideal choice for complete motor control and protection. These units allow quick and simple access to application information and configuration settings in any installation throughout a wide range of industrial segments where a three-phase induction motor needs to be controlled.

With its well-structured menu interface, the WEG SSW900 line gives users a new level of interactivity, including Bluetooth connectivity. These soft-starters provide event logs with dates and times, as well as a setup and programming assistance. The built-in bypass extends the lifespan of the units, optimising space and reducing heat dissipation inside electric panels. This built-in bypass functionality also extends throughout the WEG soft starter product range, up to 1400 Amps.

By allowing the smooth acceleration and deceleration of motors by controlling the voltage, soft-starters greatly reduce mechanical stresses on couplings and transmission devices during the start-up of a motor. In pumping applications, the smart control prevents water hammer and pressure overshoots in hydraulic piping. 

Available from Zest WEG and its network of branches and value-added resellers in current ranges from 10 A to 1,400 A – and for supply voltages from 220 V to 575 V AC – the WEG SSW900 soft-starters can operate at ambient temperatures of up to 55°C without current derating. They can substitute direct online starters or star-delta starters, bringing a range of benefits to the user’s application. These include savings in electricity, as well as greater protection and increased durability of the electric motor. 

Users also have access to diagnosis and fault history, and experience greater flexibility as the WEG SSW900 allows the installation of accessories in the application. Graphic monitoring and customisable main screens provide further convenience.  The monitoring functionality is also extended by a USB connector available on all standard products. This provides access free of charge to product software available on www.weg.net.


The G3 full line of planetary gearboxes from Zest WEG are among the world’s most robust and capable of running for 10 years before major servicing is required.

With an output torque range from 400kNm to 8,750kNm, the range boasts bearings designed for over 100,000 hours of operation. These gearboxes are popular in central drive applications in diffusers and sugar mills, where they are also used as pinion-less and assist drives. 

In addition to their high mechanical efficiency and robust gear and bearing sets, the gearboxes are flexible in their installation. The high performance hydraulic system has quality lubricant oil filtration, with 10 micron absolute filtration elements and air-oil heat exchanger for optimal cooling. 

The pioneering electronic monitoring system checks oil temperature, pressure and vibration variables to ensure the gearbox is not subject to over-torque. This guarantees smooth and reliable operation within the established limits, allowing optimum equipment usage and reduced maintenance costs. 

Manufactured in Brazil by WEG company TGM WEG, these leading gearboxes include components which are heat treated in world-class facilities in accordance with API-6 standards. Committed to quality and environmental responsibility, TGM WEG is certified in terms of ISO 9001 and ISO 14001. The company’s modern industrial complex features gear machining centres, milling machines, grinding machines, a bearing manufacturing department, a lubricating oil analysis laboratory and an assembly and testing unit for gearboxes and multipliers.

With an extensive footprint in South American market, these units are successfully operating in sugars mills in Zimbabwe and Angola. 


Establishing a strong local manufacturing base in South Africa has been integral to Zest WEG’s success over the past decade, building the economy and providing an important springboard into Africa.

This process has aligned closely with the strategic approach of Brazil-based parent organisation WEG, which prioritises its member companies’ capability, efficiency and innovation on a local level, according to Juliano Vargas, CEO of Zest WEG.

“This has required considerable investment in our local production capacity and skills base,” says Vargas. “The outcome to date has been very successful, with Zest WEG developing its local structure and supply chain , while working to world class standards and supported by WEG innovation.”

As an example, he notes that Zest WEG today achieves almost 90% local content capability for its transformers and more than 70% local content capability for other products such as E-houses and panels. These products form part of the company’s wide range of solutions, including electric motors, drives, switchgear, energy generation, electrical infrastructure, and generator sets, with different levels of localisation.

This locally developed supply chain delivers various benefits to customers, says Vargas. These include short lead times, as there is little reliance on Europe, China or the US for parts and components. 

“The impacts to our market are considerable, and we have more predictability and control of our supply chain,” he says. The company has embraced South Africa’s commitment to transformation, achieving Level 1 B-BBEE status and investing heavily in training and enterprise development. 

It helped that WEG is a member of the BRICS Business Council (representing Brazil), so it has over the years been able to engage with South African authorities about local content requirements and industry development opportunities.

“Our business – both in Brazil and South Africa – has put our weight behind economic empowerment and transformation, focusing heavily on local suppliers and local skills,” he says. 

Zest WEG’s investment in human capital exceeds the portion of payroll demanded by B-BBEE in local training. Among other initiatives is a bursary programme, and it will shortly employ its third electrical engineer from this scheme. 

Vargas highlights the powerful launchpad that this groundwork has created for growing the company’s footprint in Africa, where it also applies its local development philosophy by partnering with in-country Value Added Resellers (VARs). 


Zest WEG’s four decades in Africa have produced a powerful local manufacturing base, and a growing footprint across sub-Saharan Africa – strengthening supply chains and local economies.

“Progress in skills development has been significant in the past few years, as we have invested heavily in technology and skills transfer between the company and our holding company WEG in Brazil,” says Juliano Vargas, chief executive officer of Zest WEG. “Leveraging WEG’s global manufacturing productivity logic, we have also installed the latest equipment and systems to pave the way for a sustainable future.”

As a result, local content in the company’s manufacture of transformers is now nearly 90%, while for products like E-Houses and electrical panels has exceeded 70%. Vargas highlights the strategic importance of local content not just in terms of the mining industry’s commitment to the Mining Charter, but for the sustainability of the South African economy as a whole.

“Our local manufacturing capability has helped to strengthen the supply chain for our customers, making businesses more secure,” he says. “The value of this has been well demonstrated by the economic impact of border closures during the Covid-19 pandemic.”

Vargas emphasises that Zest WEG’s own supply chain has been actively nurtured through enterprise development initiatives, fostering the sustainability of local businesses. This local manufacturing ecosystem shields the company from market fluctuations and gives it a competitive cost advantage on locally manufactured products.

Success in South Africa has fostered growth into 47 other African countries, where customers are not only supported by wholly-owned operations but also by Zest WEG’s Value Added Resellers (VARs) in over 20 countries around the continent.

“These VARs understand their local markets and are skilled practitioners in their fields,” he says. “This ensures that they can apply Zest WEG solutions appropriately and optimally to customers’ specific needs.”

VARs are a key aspect of the company’s strategy to become rooted all over sub-Saharan Africa, collaborating with in-country experts and enhancing technical expertise and local capacity for economic development. Vargas notes that WEG’s range of products serve many industrial sectors, allowing Zest WEG and its VARs to explore opportunities not only in mining, but also in oil and gas, agriculture, water, cement and general industry.


Experienced local electrical control and instrumentation specialist E and I Zambia has successfully completed a large project on a new process plant for one of Zambia’s leading copper miners.

The contract included the installation of six electrical substations, 20 transformers, five 1,250 kVA diesel generators for backup power and a 950 metre overland conveyor. Almost 250 kilometres of cable was pulled and nearly 15 kilometres of cable racking was constructed.

Also completed were six earth mat rings, 12 mast lights and a range of general plant earthing and lighting installations around the plant, as well as the fitting and termination of instruments. E and I Zambia conducted the work between January 2019 and April 2020, in close collaboration with both a leading design house and the end-client. According to projects manager Dave Opperman, the company has a sound track record in the country, having been active on the Copperbelt and beyond since 2002.

“The experience of our team on site, the quality of our artisans and the training of workers ensured that the quality of this job was world-class,” Opperman says. “While prioritising safety and quality, we were still able to adapt to the inevitable fine-tuning of project parameters and schedules, and to deliver on the client’s timelines.”

The safety standards were well reflected in the achievement of 395 Lost-Time Injury Free (LTIF) days. This was done despite a busy site – peak manpower grew to over 270 employees and subcontractors – in a project that consumed almost 590,000 manhours. Almost all the staffing on the project was local.

“Being so well-established in Zambia, we have a solid database of skilled artisans that we can draw upon for large projects like this one,” he says. “The country has a good foundation of these trades, and we can select the most suitable profile of skills to match the project.”

A close relationship with trade unions – maintained by regular consultation – ensured that no labour issues arose that could disrupt the project, he says.

“The company maintains a comprehensive collective agreement with labour, and our collaboration means that the unions understand what the success of the project demands,” Opperman says. “This creates a win-win relationship that allows the smooth running of projects – a vital factor in the meeting of strict deadlines.”

He notes that the company is also able to optimise its local procurement through its network of reliable suppliers, while maintaining a strong cross-border supply chain for large and specialised equipment and components from South Africa.

In line with quality standards, each phase of the project involved the sign-off of both in-house and external quality control officers. This ensured that all work was done in accordance with engineering designs and industry standard specifications before being certified ready for use.

Enhancing its local expertise and experience, E and I Zambia is able to draw on the extensive technical capacity of South Africa-based EnI Electrical, an operating entity within Zest WEG.


Accommodating the space constraints of a South African platinum mining customer, Zest WEG is constructing a large diesel powered generator set to be delivered later this year.

The capacity of the 2,500kVA genset will also make it the largest unit yet to be fully load-tested at the company’s genset manufacturing facility in Cape Town, according to Craig Bouwer, projects and product manager at Zest WEG.

“In addition to functional testing, we will be equipping ourselves to conduct load testing to 11kV on this unit,” says Bouwer. “With load-banks in-house, we will be stepping the voltage down to 400V during the testing, and drawing on MV specialists to ensure a safe and reliable process.”

The genset is a highly technical solution to match the customer’s specific needs, he says. Based on the available space, it is housed within a 12 metre ISO shipping container with the electrically-driven radiator mounted on the roof.

Prime-rated at 11kV and powered by an MTU diesel engine, the genset has been designed in close consultation with the customer over a number of months. Having concluded the engineering design, construction is currently underway in Cape Town. Bouwer highlighted the detailed and time consuming nature of engineering design for a project of this magnitude and complexity.

“Stringent technical requirements demanded lengthy and ongoing collaboration not only with the customer, but between our engineering team and production operations,” he says. “The customer was particularly pleased with our flexibility and the extra effort we applied to ensure the optimal technical returnables for the project.”

As one of the few Original Equipment Manufacturers (OEMs) capable of undertaking a customised genset of this capacity in-house, Zest WEG will also be supplying the control and protection panel from its extensive range of electrical equipment and products.

“To enhance safety and ergonomics, the control panel is in its own compartment within the ISO container,” he says. “A 1,000 litre bunded day tank has also been installed inside a separate compartment within the container, including a fuel cooler and filtration system.”

The Covid-19 lockdown has had minimal impact on the work schedule, he notes, as planning and communication with the customer could continue regardless, dealing with various technical clarifications. To facilitate the transportation of this large unit to site, it will be shipped as three separate components: the genset, radiator and exhaust system. Once installation is complete – a process that Zest WEG specialists will supervise – its experts will conduct the cold and hot commissioning, and hand over to the customer.