Tag Archives: Zest WEG Group


Africa has embraced the innovation that drives WEG products and services, with customers seeing value in constant technological improvement.

Siegfried Kreutzfeld, CEO of the South African based Zest WEG Group, explains that WEG is quick to introduce its new products into the African market, sometimes even before launching elsewhere in the world.

“We pride ourselves on the significant investment we, as WEG, make in research and development,” Kreutzfeld says. “About 2,6% of our net revenue is ploughed back into continuous product improvement as well as new development. This keeps us at the cutting edge of technology.”

The result of this intense commitment to innovation is that 43,7% of all WEG products sold in 2018 were launched in the last five years. Another indicator is that Brazil-based WEG Group holds 174 patents that are used on its products.

Significantly, this has placed WEG among the thousand most innovative companies in the world, ranked by The Global Innovation 1000 of 2014. This world ranking evaluates the total R&D investments of each company, including the strategy, purpose and success of these investments.

“More than 35 years ago, we led the way in South Africa by introducing reliable high performance motors into the mining sector,” he says. “Today, we have a solid market share on the continent based on the trust we have built with our customers. This relationship makes it easier to introduce and test new WEG technologies in Africa.”

While continuously improving its products, WEG also closely monitors how they perform in the field, Kreutzfeld notes. “An indicator of the confidence we have in WEG technology is that we provide a five year warranty on WEG motors,” he says. “This is unique on the continent and difficult for competitors to match.”

WEG’s innovation and the market trust are paying dividends. Despite the country’s poor overall economic performance, Kreutzfeld says Zest WEG Group is targeting 15% growth with its high quality offerings.

Among the latest WEG technologies are energy-efficient IE3 motors which reduce electricity consumption, and the WEG CFW 11 Variable Speed Drive (VSD) which selects the best efficiency, again conserving energy and saving costs.

Kreutzfeld says that during 2019 a new series of WEG VSDs, specifically for mine fan applications, will be introduced to the market.

WEG’s innovative Motor Scan device is another important development, harnessing connectivity and the power of Industry 4.0 technology to monitor motor health. Attached to the motor itself, the WEG Motor Scan gathers vital data including vibration, temperature and running time. This is communicated wirelessly to a hand-held device or to WEG’s Internet of Things (IoT) platform.

“Extending electric motor life is going to be an important trend in the market, especially in the mining sector,” Kreutzfeld explains. “Only a decade ago mines expected less than two years of life from an electric motor, and we have been able to change that. Using Motor Scan will allow end users to optimise routine maintenance and extend motor life.”

Another technological innovation is the large WEG slipring motors considered ideal for the cement industry. Cement plants place high wear demands on electric motors, and WEG has developed features to address this challenge.

“We innovate by being close to our customers and seeing the problems they face,” he says. “You cannot pursue innovation without understanding customer applications and market trends.”

To drive this process, WEG established a Scientific and Technological Committee in 1998. This forum allows WEG’s engineering team to engage with five university specialists, three from abroad and two from Brazil. The forum meets every two years to discuss market trends, technology and innovation, and importantly how to apply this to WEG products.

“During this meeting, we share new concepts and products with the academic experts,” he says. “This collaboration has many mutual benefits. We gain ideas and feedback, and the universities can gather topics for their students to research.”

Inside WEG itself, there is a team focused on new product concepts and technologies. Kreutzfeld says many of these might remain in development for years, even decades, and are only commercialised in response to market trends.

“This pipeline of innovation is vital to meet changing customer needs and is what sets WEG apart,” Kreutzfeld concludes.


Two units of the newly developed WEG 11 kV Variable Speed Drive (VSD) have been commissioned in West Africa by WEG Automation Africa, a member of the Zest WEG Group.

According to Kirk Moss, senior manager: projects and engineering at WEG Automation Africa, the new WEG MVW3000 VSD is a valuable addition to its Medium Voltage (MV) VSD portfolio. The first two 11 kV units produced are for 850 kW ventilation fan motors in an underground gold mine in Ghana.

“In line with WEG’s ongoing innovation, the addition of the WEG MVW3000 system brings a range of benefits to customers,” says Moss. “It gives WEG Automation Africa even greater flexibility in our market offering, further enhancing our capability to provide customised solutions.”

The design is based on the well-known cascaded H-bridge (CHB) topology, using multiple low voltage power cells in combination to achieve the desired voltage output. The input switch, phase-shifting transformer and VSD are fully integrated in a single MV panel.

“The WEG MVW3000 is particularly suited to applications where there are standard motors with no special insulation,” he says, “or where existing motors are being modified for VSD control.”

This VSD delivers high quality input power using low harmonic multi-pulse transformers. Users benefit from a high efficiency of over 96.5% throughout the entire load range, and a power factor of more than 0.95 throughout the entire speed range.

“The design includes power cells with long-life plastic capacitors, which are more reliable and last longer than dry type capacitors,” he says. “They also have the advantage of not needing to be reformed after long periods of storage.”

In standard configuration, the 11 kV VSD is available from 40 A to 400 A – or 640 kW to 6500 kW – although larger sizes are also available if required.

Among the options on the WEG MVW3000 is an automatic cell bypass solution. This ensures minimal reduction in the output-rated torque so that normal operations can continue. Redundant power cells can also be added to the design to ensure that 100% torque can be maintained. Prior to delivery, all VSDs are fully load-tested in WEG’s state-of-the-art facility in Brazil.


The applications knowledge of Zest WEG Group, coupled with the design capability of parent company WEG, now make it easier than ever for old high voltage (HV) motors to be replaced with new, improved HV machines within the customer’s existing footprint and operational configuration.

Compared to HV machines designed 20 to 30 years ago, advances in technology allow for these HV units to often be manufactured smaller than the originals, says David Spohr, Zest WEG Group’s newly appointed business development executive. He works with customers to optimise their HV motor operations.

WEG’s HV motors are typically purpose-built to meet the precise needs of the customer. While smaller in dimensions compared to the original older HV motors, these motors still deliver the required performance at even higher output and efficiencies.

“As a leading technology provider of a wide range of motor products, we have the capability to design a replacement motor to match the footprint of the original unit,” Spohr says. “This means it is not necessary for the customer to modify mechanical infrastructure or electrical design to accommodate an upgraded motor.”

He notes that, with the design lifespan of electric motors which ranges between 20 to 30 years, there are still many old units in operation around South Africa. Technological improvements in motor design and efficiency, however, present a compelling case for the replacement of old units rather than repeated repairs.

Spohr highlights that the cost of a major motor overhaul could be up to 60% of the cost of replacement. The advanced technology of the new units, however, bring important benefits. Key among these are reliability and efficiency, which means improved operational performance and direct savings in energy consumption

“When motor failures occur, Zest WEG Group has the ability to conduct a detailed on-site analysis,” Spohr says. “Based on a root-cause analysis, we can provide a failure assessment which will enable the customer to make an informed decision.”

The assessment includes an energy consumption analysis conducted with specialised software. In the light of the machine’s application, Zest WEG Group recommends enhancements for greater control and efficiency. These include motor control options such as variable speed drives (VSD) for applications such as fans and pumps.

“There are also significant productivity benefits from a new, more reliable motor,” says Spohr. “Unplanned downtime can severely erode plant performance, reduce output and risk supply relationships with customers. All this needs to be considered in the decision to continue repairing old motors.”


The increased move towards the use of IE3 electric motors has made it increasingly important that the most appropriate starting method be selected to ensure optimum performance.

With this move it is essential that the motor switching and protection components are engineered to meet the demands of the IE3 motor.

Generally, the most basic starting method for an electric motor would be a direct online starter or star delta starter, however older generation switchgear has not been engineered for IE3 motor compatibility.

Older generation switchgear may generate nuisance tripping. Not only is this undesirable, it can also have a severe knock-on effect in terms of operational productivity and efficiencies.

WEG IE3 compliant low voltage switchgear has been engineered to offer absolute reliability when using WEG switchgear to start and operate WEG IE3 motors. Users can be confident that when using WEG IE3 compliant switchgear, their drive system will provide the highest levels of energy efficiency over a long service life. This will, in turn, translate into a reduction in the total cost of ownership (TCO) while complying with current environmental regulations.

WEG Motor Protective Circuit Breakers
Typically, motor protective circuit breakers are affected most when starting electric motors because of sensitivities to transients and instantaneous values of current.

WEG circuit breakers were evaluated specifically in terms of this and the multiple of short circuit release was changed from 12 to 13 times the rms value of the rated current. Following this modification, extensive testing was conducted to verify that, with these modifications, the whole range of WEG circuit breakers is IE3 compliant.

WEG Contactors
The entire range of WEG contactors is IE3 compliant. The application of sound engineering principles ensured that there is no mechanical or electrical lifespan reduction, or an increase in the contactor’s coil consumption.

WEG Overload Relays
Overload relays are designed to protect motors thermally against overload conditions and unlike motor protective circuit breakers these are not sensitive to instantaneous currents. WEG solid-state and thermal overload relays conform to IE3 motor application

Significantly, as a leading manufacturer of premium (IE3) and super-premium (IE4) electric motors, WEG has developed extensive expertise in IE3 equipment conformity and all WEG’s current switchgear and protection devices can be used without restriction to ensure the reliable operation of IE3 motors.

Zest WEG Group’s technical team is able to assist customers in the appropriate selection of IE3 compliant control and protection components to optimise the efficiency of motor installations.

New products are continually being added to the WEG low voltage switchgear range, leveraging off the ongoing research and development conducted by WEG Brazil. These products are available off the shelf from the Zest WEG Group and include contactors, motor protection relays, motor circuit protection breakers, push buttons and indicating lights, field isolator stations, motor starters in either polycarbonate or sheet metal enclosures and other associated products.

Backed by SABS certification, the WEG switchgear product range is gaining popularity in the mining, general industry, commercial and domestic sectors. Among the leading products in the range is the WEG CSW range of push buttons and pilot lights, now available in complete sets; contactors and thermal overload relays; direct online starters; a full range of miniature circuit breakers and the most intelligent product in the range — the innovative SRW01 smart relay for protecting motors of high value and preventing extended downtime. This low voltage electric motor management system incorporates state-of-the-art technology and network communication capabilities, and its modular concept makes it suitable for a variety of applications.

A full catalogue of WEG switchgear products is accessible online through the Zest WEG Group’s website at www.zestweg.com. These products are sold out of a sales centre at the company’s Linbro Business Park facility in Sandton, easily accessible from Johannesburg, Pretoria and Krugersdorp.


South Africa could go a long way to cut the risk of future load-shedding by adopting a minimum efficiency performance standard (MEPS) for electric motors.

According to Fanie Steyn, manager rotating machines at Zest WEG Group, a MEPS would significantly reduce the peak power demand on the national grid. Importantly, the step could be made at no cost to government and would also bring substantial savings to industry’s electrical energy costs.

“The MEPS would phase out the least-efficient electric motor classes by setting a minimum standard for the efficiency of motors imported and sold in South Africa,” he says. “The essential challenge now is that about 280,000 electric motors are imported each year, many of which are low efficiency motors rated at IE1 level as standard.”

Steyn highlights the great strides recently achieved in the efficiency of electric motors. Energy savings of between 2,1% and 12,4%, depending on the individual power rating, can be made by converting from a standard efficiency IE1 motor to a premium efficiency IE3 motor. The capital cost differential is slight and is quickly recouped by lower operating costs.

“It is estimated that as much as 30% of all energy produced globally is consumed by electric motors,” he says. “It is therefore easy to see why improving motor efficiencies has a huge impact on national energy consumption.”

It is significant that more than 42 countries already have MEPS in place. These standards apply mostly to three-phase low voltage motors from 0,75 kW to 375 kW capacity. The MEPS is applied at import stage, so the process would be handled in the conventional manner by customs agencies.

“If the 150,000 low voltage motors entering the country each year were IE3 rated instead of IE1, the national grid could be relieved of about 195 million kWh in a single year,” says Steyn. “This means almost three billion kWh over the next five years.”

He adds that this would also mean lower carbon emissions from power stations. South Africa has committed to reduce these emissions by signing the Paris Agreement in 2016.

“Implementing MEPS will have significant benefits for everyone,” Steyn concludes.

The Zest WEG Group, a subsidiary of leading Brazilian motor and controls manufacturer WEG, has a strong commitment to contributing to the development of the African region, and has been servicing the continent for more than 37 years.


Shaw Controls, a member of the Zest WEG Group, has designed, engineered, manufactured and supplied a fit-for-purpose E‑house solution into an oil and gas sector application at a major South African port.

Bevan Richards, managing director of Shaw Controls, says using a draft concept supplied by the customer the company has taken its E-house design and manufacturing capabilities to new heights.

Shaw Controls was responsible for the complete mechanical and electrical design as well as manufacture of this E-house solution which comprises five modules.

Richards says probably in a ‘first’ for South Africa and accommodating space constraints on site, the design is a multi-level construction which will be fitted onto the available footprint. This E-house solution comprises three modules at ground level with two above.

The substantial structure, including all electrical substation equipment, weighs approximately 90 tonnes. A section of the ground floor houses a medium voltage (MV) switchroom with a dry-type transformer for enhanced safety, and a module fitted with three 450 kW MV variable speed drives (VSDs).

The third module contains a 1 MVA generator set, sourced from Zest WEG Group’s dedicated genset manufacturing facility in Cape Town, for backup power.

The first floor comprises one module with a low voltage motor control centre (MCC) and four freestanding low voltage (LV) VSD panels, and a second module for control and automation.

An additional E-house comprising one module for a separate (LV) substation has also been supplied.

“Our expertise and experience in designing appropriate mechanical and electrical solutions using 3-D modelling software makes this kind of innovation possible,” says Richards.

Using a turnkey approach allows Shaw Controls to efficiently construct the full solution at its dedicated E-house facility in Heidelberg, saving customers the complexity of managing multiple contractors on site. At this facility, the modules are trial-fitted, assembled and tested before transportation to site.

“As with our other E-house projects, we are able to provide quality assurance before units leave the facility, reducing the various risks and costs of on-site construction and commissioning including requiring specialised resources,” he says.

Other important aspects of this E-house design include its fire rating, fire detection systems and HVAC systems for heating, cooling and ventilation. Rock wool mineral insulation between the cladding segregates the modules and provides a two hour structural fire rating. Climate control systems will ensure that the coastal temperatures and humidity of KwaZulu-Natal do not disrupt smooth operations.


Fast payback on steam turbine cogeneration systems makes this power source an attractive option across numerous industries.

This is according to Leandro Magro, manager steam turbines at Zest WEG Group, who explains that any industry with a boiler installed has a potential for cogeneration using a steam turbine. “The electricity cost savings usually pay back the investment in less than three years, but this payback period can be further reduced depending on the applicable electricity price tariff in effect,” he says.

Power plants, sugar mills, pulp and paper mills, steel mills, petrochemicals, oil and gas installations, food and beverage manufacturing operations and many other industries including commercial and institutional facilities use steam turbines for electricity production or to drive mechanical equipment such as compressors, fans, mills and blowers.

When used for the production of electricity, the steam turbine is coupled to a generator, which is commonly referred to as a steam turbo generator set. Magro says that typically, industrial steam turbine models start from a 30 kW capacity and go up to 150 MW. “These turbines can operate at a very low steam pressure (5 bar or less) or a high steam pressure up to 140 bar, saturated or superheated steam up to 540°C,” he says.

“The operational availability of an industrial steam turbine should be about 98%, however a proper maintenance programme is essential not only for prolonging the life of the equipment but also to ensure the correct operation of the turbine,” Magro says.

The best way to achieve this is to enter into a service contract with the OEM who will recommend an appropriate maintenance and service programme. A new steam turbo generator set could be installed in the plant to operate in parallel with the pressure reducing valve, so when maintenance is required on either the valve or turbine, the processes which require steam would not need to be stopped.

“Steam turbine cogeneration is not only suitable for large installations but can play a vital role in medium and small applications, saving the end-user a significant amount in energy costs over the expected life span of the system which depending on design can vary from 20 to 30 years,” Magro concludes.


WEG Automation Africa and WEG Transformers Africa, part of the Zest WEG Group, assisted with the commissioning of a containerised substation and control room solution at DRDGOLD’s new Far West Gold Recoveries Project’s Phase 1 tailings site.

The tailings recovery project will see 500 000 tons per month of material pumped from the Driefontein 5 dam through a new 2 km pipeline to the Driefontein 2 plant. Business development manager for projects and contracts at WEG Automation Africa, Tyrone Willemse highlights the tight timelines in which work had to be conducted.

The development of Phase 1 began in August 2018 with first commissioning beginning just four months later, in December 2018. In an unusual step for such a project, the electrical portion was supplied ahead to the mechanical aspects to expedite the contract.

“At the tailings facility, the customer required a medium voltage (MV) substation, a low voltage (LV) substation and a control room,” Willemse says. “This was accommodated within a double-container structure, which also included a room to house all the free-standing variable speed drives (VSDs) and uninterruptible power supplies (UPSs).”

The container was mounted on a concrete plinth with 2,5 metre pillars elevating the structure to allow optimal visibility from the control room. Heat losses were factored into the design to ensure the substation remained cool and the installation is fitted with a comprehensive fire detection system.

Willemse says that an important consideration was to reduce the footprint of the substation, and using free-standing VSDs allowed this. “Had the VDS configuration been a conventional design these units would have been incorporated in panels and we would have needed an additional container,” he says. The VSDs are placed against the container wall and are completely isolated from any exposed conductors.

Motor Control Centres (MMC) were also provided for the modifications to the Driefontein 2 plant. The MCC for the thickener is fed by two 1600 kVA transformers and the tailings MCC is fed by one 1600 kVA transformer; both were manufactured at WEG Transformers Africa’s Wadeville facility. Significantly, these WEG transformers have a local content of 95%, well over the required 90% specification.

“For this project, the transformers are designed to incorporate the VSD component of the load, and this demonstrates the engineering flexibility that WEG Transformers Africa can offer customers in meeting specific operating parameters,” Stuart Brown, sales team leader at WEG Transformers Africa, says. “It is not a distribution transformer as such, but rather a VSD-type transformer.”

Cooling capacity had to be increased to accommodate the harmonics, and flux density is also reduced. The WEG transformers are built to SANS 780 specification, which stipulates losses even lower than the global IEC standard. Brown explains that this will translate over time into energy savings for the customer and is an important advantage.

Fabrication of all MCCs and the adaptations to the container were undertaken by WEG Automation Africa at its facilities in Robertsham, Johannesburg and Heidelberg, further adding to the high local content on this project. This local manufacturing capability is an integral part of Zest WEG Group’s status as a B-BBEE Level 1 contributor.

Particular care was taken with on-site modifications at the plant itself. At the milling and classification MCC extension, WEG Automation Africa was required to connect to DRDGOLD’s existing MCCs. The use of joggle chambers on either side of the existing board made for best practice and greater safety. On the return water MCC, a raised plinth was added for easier cable access. Top entry cables for the slurry receiving and tailings MCC was facilitated by innovative board design.

The MCCs incorporate an extensive range of WEG LV products including WEG air circuit breakers (ACBs) to facilitate a 50 kA fault level, WEG moulded case circuit breakers (MCCBs), WEG contactors, WEG fast-acting high rapid fuses, and WEG motor protection relays.

WEG W22 LV electric motors were selected to drive the tailings facility pumps, ensuring lower energy consumption through the design of these units, which have an optimal cooling fin design. Ingress protection is to IP66 ensuring effective sealing against liquid and dust.

WEG Automation Africa, formerly known as Shaw Controls, recently changed its name to align with parent company, Brazil-based WEG’s global strategy. Its local manufacturing operation has been the recipient of an extensive investment programme by WEG that has seen its facilities upgraded as part of the ongoing commitment to the South African economy and customers in the region.


According to Zest WEG Group, there are misconceptions around what constitutes ‘earth’ (or ‘ground’) and ‘neutral’ connections and not understanding the differences can create serious problems when connections are made from on-site transformers or other sources. This more often than not leads to earth leakage systems underperforming and compromising the safety of the equipment and operators.

Johan Breytenbach, transformer sales specialist at Zest WEG Group, says that the neutral connection in an electrical installation is designed to carry current all the time, while the earth connection is only supposed to carry current for a short period to trip your protection switch.

“Where this is not understood and the installation is not done correctly, the trip system will not work properly. In addition to this, stray currents are created that could cause other problems,” he says.

Experience has shown that many farmers use the neutral connection as the earth when they do an electrical installation, and this is not correct. Current carried on a grounding conductor can result in significant or even dangerous voltages on equipment enclosures. For this reason, the installation of grounding conductors and neutral conductors is carefully defined in electrical regulations.

In alternating current (AC) electrical wiring, the earth is a conductor that provides a low impedance path to earth so that hazardous voltages do not find their way to the equipment. Under normal conditions, the earth connection does not carry any current. Neutral, on the other hand, is a circuit conductor that normally carries current back to the source.

Neutral is usually connected to earth at the main electrical panel or meter, and also at the final step-down transformer of the supply. Neutral is also the connection point in a three-phase power supply to connect cable termination in order to gain single phase power. In a three-phase circuit, neutral is usually shared between all three phases, with the system neutral being connected to the star point on the feeding transformer.

Earthing is therefore a vital part of electrical installations to ensure that circuit breakers will trip under fault conditions. Safe and legal installation needs to start with the selection of the right transformer, with a star configuration to allow the connection to the neutral point. Installation by a qualified and experienced technician is then ideal, to ensure optimal performance.

The correct earthing or grounding of electrical currents has a number of important benefits apart from the main concern around safety. It protects equipment and appliances from surges in electricity – commonly from lightning strikes or power surges – which bring dangerously high voltages of electricity into the system. Good earthing will ensure that excess electricity will go into the earth, rather than damaging equipment.

Zest WEG Group’s product line-up includes low and high voltage electric motors, vibrator motors, variable speed drives, softstarters, power and distribution transformers, MCCs, containerised substations, mini substations, diesel generator sets, switchgear and co-generation and energy solutions as well as electrical and instrumentation engineering and project management services.


As Sandton anticipates the completion this year of the Leonardo, the top-end mixed-use skyscraper being constructed by Aveng-Grinaker LTA, Level 1 BBBEE-rated Zest WEG Group has supplied generator sets to keep lights on during outages. The iconic structure, that will dominate the skyline as the tallest building in Africa, is being built for 75 on Maude (Pty) Ltd, a partnership between Legacy Group and Nedbank Limited.

According to Craig Bouwer, projects and product manager at Zest WEG Group genset division, the commissioning of the units was undertaken in the first quarter of 2019 with practical completion expected to be reached in the second quarter of 2019. This follows the original awarding of the tender in November 2017.

“We are proud to have designed, manufactured and supplied the two 2,000 kVA, 11 kV generator sets which we are installed in the Leonardo’s dedicated plant room on ground level,” says Bouwer.

“Our contract included delivering the units to site and placing them in position, which was done in September last year. We were also responsible for the complete installation, testing, commissioning and handing over to the client in full working order.”

The gensets will provide the building with emergency power backup and comprise prime-rated Mitsubishi-powered diesel generators coupled to WEG alternators. To reduce noise levels to local council requirements, Zest WEG Group supplied and installed inlet and outlet splitter attenuators. The fuel storage and transfer system ensures eight hours of operation, with bulk and day fuel tanks installed in compliance with local fire regulations.

The company also installed medium voltage (MV) generator protection and a control panel, as well as a main MV distribution panel for the building, comprising six tiers for all incoming supply and feeder breakers. All the related cabling for the MV and low voltage (LV) reticulation were also provided for the generator sets, fuel system and auxiliary control equipment.

Significantly, Zest WEG Group holds a Construction Industry Development Board (CIDB) rating of 6EB for electrical engineering work in buildings, as well as a 9EP rating for infrastructural electrical engineering work.

“We conducted full in-house MV testing of the system at our modern Cape Town facility before delivery to site,” Bouwer says. “We were assisted by our transformer division with the supply of three 500 kVA, 11 kV to 400 V step-down transformers to enable load testing at 400 V. This allowed us to conduct functional and load tests on the generator sets in our workshop, testing them individually as well as in full synchronisation and load share operation.”

Bouwer adds that the location of the generator plant room and the physical size of the generator sets meant that the generator sets could not be installed as fully assembled units.

“This challenge was overcome by disassembling the generator sets prior to delivery and re-assembling them in the generator plant room,” he says. “Due to the weight of the equipment, special rigging equipment was required inside the plant room to facilitate the re-assembly process.”