Tag Archives: Zest WEG Group


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.”


As part of its ongoing growth plans, Zest WEG Group will continue to focus on opportunities in more African countries, according to its new chief executive officer, Siegfried Kreutzfeld.

With 40 years of service in the global WEG Group, Kreutzfeld brings a wealth of industry experience to the top job at the South African business, which he joined in January 2019. He was most recently the managing director of WEG China.

“WEG has a very simple strategy: we believe in continued growth on all continents,” he says. “This is achieved by maintaining close relationships with all our customers and ensuring that we deliver quality products. We underpin all this by our high levels of service and support.”

Established in South Africa to create a strong national footprint, the Zest WEG Group has grown steadily into other Africa countries. With its responsibility for the sub-Saharan market, it operates branches in Ghana, Tanzania, Mozambique and Namibia. The group also has competent partners in countries like Angola, Botswana, Zimbabwe, DRC and Zambia. Today, the Zest WEG Group ranks among the top five operations in the global WEG Group.

“Many of our products are well established across the continent,” he says. “However, we believe there is growth potential with both mature products – such as low voltage motors, high voltage motors, and drives and switchgear – as well as with other products we manufacture locally such as transformers, motor control centres, panels and generators.”

Kreutzfeld highlights that major opportunities exist with premium efficiency products across the range, including WEG IE3 motor and WEG CFW drives.

“Also key to the Zest WEG Group’s growth potential is our ability to offer a fit-for-purpose integrated solution,” says Kreutzfeld. “This is available across all sectors, but especially in power generation, electrical infrastructure and mobile power and energy solutions. We will also be introducing WEG solutions for renewable energy applications.”

The wide range of products in Zest WEG Group’s market offering are relevant across a broad sector of industries including mining; petrochemical; agriculture; water and wastewater; paper and pulp; sugar; and energy – including traditional coal fire power plants and renewable energy.