Tag Archives: Zest WEG

Zest WEG E-House powers up HIG mill at South Africa platinum mine

A purpose-designed electrical house (E-House) from Zest WEG is driving one of the largest new high intensity grinding (HIG) mills in the southern hemisphere, recently installed at a platinum mine in South Africa’s North West province, Zest WEG says.

The size and operational parameters of the mill place demanding requirements on the equipment in the E-House, according to Tyrone Willemse, Senior Proposals Manager at Zest WEG. Constructed in South Africa incorporating a range of products – produced and distributed by Zest WEG – the E-House design also delivers world-class standards of safety and fire protection, the company said.

“The key benefit of the prefabricated E-House concept is the time it saves the customer and the high level of quality that can be ensured through its construction and testing under ideal workshop conditions,” he says. “The process is also streamlined as the complete project falls under a single provider, who takes full responsibility for delivering on-time and on-budget.”

This E-House includes the HIG mill’s variable speed drive (VSD) and all its associated auxiliary circuits and starters. A range of WEG transformers and motors are also part of this project. With its extensive in-house expertise, Zest WEG generates fully detailed designs for its E-Houses, using 3D computer assisted design software.

“For this application, the E-House consists of a medium voltage room and a low voltage (LV) room,” Willemse notes. “The MV room houses the well-known WEG MVW01 VSD, with an integral oil type 12 pulse transformer manufactured locally at our transformer manufacturing facility in Wadeville.”

Willemse explains that the WEG MVW01 makes use of high voltage insulated-gate bipolar transistors, which lower the amount of power electronics needed. This also reduces the mean time to repair, so that operations can be quickly restored in the event of a major fault on the system.

“The WEG MVW01 powers a WEG 3.75 MW MGR eight pole 3.3 kV directly-coupled squirrel cage induction motor,” says Willemse. “This motor is specially designed to be vertically mounted to meet the HIG mill’s operation and maintenance requirements.”

Both the motor and the VSD were designed to meet the aggressive torque requirements during some phases of the mill’s operation. The combination handles the torque requirements that periodically exceed 170% for more than three minutes, giving the customer the necessary flexibility, according to Zest WEG. The LV room contains the motor control centre (MCC) that feeds all the auxiliary circuits of the mill.

“Importantly, we have installed the newly arc-proof type-tested IEC 61641 WEG board, which has the best rating for personal protection,” Willemse says. “In the event of an internal arc, the MCC is fitted with an explosion duct that transfers any explosion safely out of the building.”

Another aspect of the safety features is a fire detection and suppression system that meets the customer’s demands. The two rooms are fitted with their own fully automated room-flooding suppression systems, which can flood the space with gas that douses electrical fires but is not dangerous to humans.

“The system can detect smoke at a very early stage, and can also check against false triggering,” Willemse says. “More than two smoke detectors must react, activating a loud bell for evacuation or cancellation, before flooding takes place.”

The LV room also houses WEG CFW11 LV VSDs, which feed premium efficient WEG motors. The E-House’s small power and lighting circuits are fed by one of Zest WEG’s locally manufactured SANS780-compliant transformers.

Zest WEG motors, VSDs help drive Kamoa-Kakula to reaching copper production goals

Zest WEG says it is supplying an extensive range of motors and variable speed drives (VSDs) for the second phase of the Kamoa-Kakula project, in the Democratic Republic of the Congo.

Phase one of the project produced its first copper concentrate on May 25, 2021, and is expected to produce 200,000 t/y of copper in concentrate, according to Ivanhoe Mines, which owns 39.6% of the project, along with Zijin Mining Group (also 39.6%), Crystal River Global Ltd (0.8%) and the Government of the Democratic Republic of Congo (20%).

Phase 2, now in the advanced stages of construction, will result in a doubling of production capacity. Future phased expansions could eventually see a mining rate set to process 19 Mt/y.

For the first phase of the project, Zest WEG was the key supplier for this electrical equipment.

According to Joe Martins, Mining Sector Specialist for Zest WEG, the mine’s scope of supply for the second phase is a repeat of the first. The first phase was supplied in 2020 with WEG medium voltage VSDs and WEG high voltage motors to drive the mine’s primary and secondary mills in the concentrator plant.

“We began to manufacture these long-lead time items in 2019, and delivered two medium voltage VSDs and two 3.3 kV motors for the mine’s 7,000 kW primary ball mill and its 7,000 kW secondary mill,” Martins said. “Our high voltage motors and medium voltage VSDs were also selected to drive the two 1,200 kW high pressure grinding rolls in the plant.”

WEG high voltage motors and automation solutions drive the underground ventilation fan applications, providing fresh air to the underground mine workings, he added.

All these large items are designed to specification, manufactured and tested in WEG’s Brazil facilities.

Due to COVID-19 travel restrictions, the factory acceptance tests were conducted virtually, with special processes being developed to allow thorough inspection and comment online. The testing of the equipment for phase two – also conducted in a virtual environment – was completed in the September quarter of 2021.

Kamoa-Kakula is expected to become one of the world’s lowest greenhouse gas emitters per unit of copper produced, and Zest WEG’s energy efficient motors and automation solutions will contribute to this, the company said.

The first phase order included over 700 WEG low voltage IE3 premium efficiency motors, supplied to various local and international original equipment manufacturers, and installed throughout the concentrator plant. These motors drive equipment such as the rock breakers, conveyor drives, flotation cells, thickeners, slurry pumps, winches and other mechanical OEM packages.

Where processes within the plant required variable speed control, WEG low voltage VSDs were selected to provide the speed and control necessary for this equipment. Martins explains that, by selecting WEG low voltage VSDs in combination with WEG low voltage motors, Kamoa-Kakula will benefit from a 36-month warranty period.

“An important part of the energy efficiency strategy was for the plant to standardise on our IE3 premium efficiency motors – rated according to the IEC 60034-30 international standard,” he said. “With a class-leading energy efficiency rating, this means reduced carbon emissions and greatly reduced operational energy costs.”

Additionally, Zest WEG is supplying the Kamoa-Kakula project with a new 20 MVA, 33 kV/11 kV mobile substation, which is currently being manufactured in South Africa. The substation will provide stepped down power, and can be moved to supply power to different areas within Kamoa-Kakula’s mining footprint.

“Underpinning the performance of our equipment at the mine will be high levels of service and support from Panaco who is our Value Added Reseller in the DRC,” Martins said.

E and I Zambia helps power up process plant for copper miner

Electrical control and instrumentation specialist, E and I Zambia, says it 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 back-up power and a 950 m overland conveyor. Almost 250 km of cable was pulled and nearly 15 km of cable racking was constructed, according to the company.

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, the company said.

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 reflected in the achievement of 395 Lost-Time Injury Free days. This was achieved 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, the company said.

“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,” Opperman says. “The country has a good foundation of these trades, and we can select the most suitable profile of skills to match the project.”

He noted 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 all work was carried out in accordance with engineering designs and industry standard specifications before being certified ready for use.

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

Zest WEG helps South Africa platinum miner power up

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

The capacity of the 2,500 kVA genset will make it the largest unit yet to be fully load-tested at the company’s genset manufacturing facility in Cape Town, South Africa, 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 11 kV on this unit,” Bouwer says. “With load-banks in-house, we will be stepping the voltage down to 400 V 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 m ISO shipping container with the electrically-driven radiator mounted on the roof.

Prime-rated at 11 kV 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 said. “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 South Africa-based original equipment manufacturers capable of undertaking a customised genset of this capacity in-house, Zest WEG will also be supplying the control and protection panel from its range of electrical equipment and products.

“To enhance safety and ergonomics, the control panel is in its own compartment within the ISO container,” Bouwer 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 noted, 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.

Zest WEG signs up Panaco to grow footprint in key DRC mining hub

Zest WEG, in an effort to strengthen its Africa footprint, has appointed Panaco as its value-added reseller (VAR) in the Katanga region of the Democratic Republic of Congo (DRC).

According to Zest WEG’s Africa Business Development Executive, Taylor Milan, Panaco is a 100% locally-owned business that has successfully serviced the region, known for mining, for over 40 years.

“Panaco is a well-established and respected company with strong business relationships with nearly all of our current clients,” Milan said. “Its business methodology and culture are closely aligned with ours, and this synergy will aid us in supporting our current installed base, client network and growth expectations.”

Milan highlighted the increasing importance of local content in the supply of equipment and services across the continent. Therefore, Zest WEG has prioritised closer partnerships with local firms as a key element of its sustainable growth strategy in Africa, a strategy Zest WEG Group CEO, Siegfried Kreutzfeld, mentioned shortly after being appointed to the role in 2019.

Milan also emphasised the importance of VARs in this strategy.

“Going beyond the role of just a distributor, a VAR is a local business chosen to promote and support the wide range of Zest WEG’s offering,” he said. “It carries the whole Zest WEG brand into local markets.

“Panaco has the ability to assist us in growing the comprehensive WEG product portfolio well beyond our traditional low-voltage motor and drive business,” he said. “It has business facilities in Lubumbashi, Kolwezi and Kinshasa – bringing our services and support closer to customers in this fast-growing region.”

The VAR partnership will provide locally accessible support and skills, substantial stockholding, and quality products at competitive pricing, the company said. It will also build strong and service-oriented customer relationships, according to Milan.

Zest WEG has also appointed DRC firm AEMI as a WEG-accredited repair facility, after AEMI successfully met its OEM standards. The company has a full repair facility in Likasi, and another in Kinshasa.

Zest WEG keeps DRC mining project on track in face of COVID-19 restrictions

The Zest WEG Group, a subsidiary of leading Brazilian motor and controls manufacturer WEG, is intent on keeping its customers’ projects on track despite COVID-19-related travel restrictions and has devised a way to complete the final step in the manufacturing process remotely.

In an innovative first to keep a customer’s mining project in the Democratic Republic of the Congo on schedule, Zest WEG successfully conducted a remote witness test of medium voltage (MV) variable speed drives (VSDs) in WEG’s Brazil factory.

David Spohr, Business Development Executive for high-voltage equipment at South Africa-based Zest WEG, said these extraordinary times called for extraordinary measures.

“With the restrictions on international travel, we had to think creatively about how to complete this final step in the manufacturing process – the witnessed factory acceptance test (FAT) – before the equipment could be shipped to the DRC site,” he said.

Under normal circumstances, these tests would require the customer to travel to Brazil and spend a week at the factory witnessing and signing off a range of detailed test and equipment requirements.

This order comprised two 7 MW, 3,300 V WEG MVW01 VSDs for the ball and SAG mill drive application and two 1.2 MW, 3,300 V WEG MVW01 VSDs for the high pressure grinding roll (HPGR) mill application. Both applications required non-standard features, according to the company, namely “frozen charge protection” software on the ball and SAG mill application and a “master and follower” configuration on the HPGR mill application, it said.

Spohr said: “It was essential that we did not delay the customer’s project, so we arranged to conduct the witness test using web-based communication software. This allowed the participation of Zest WEG experts, the engineering contractor and the end user, all from the safety of their homes in Johannesburg – communicating with five testing technicians in the WEG factory in Brazil.”

Using a high-definition camera and web-based communication software, the factory technicians were able to walk the contractor and end user through each element of the FAT, with clear and real-time visual images of the test results and equipment on the factory floor, according to the company.

The tests continued for three days, beginning at 13:00 and ending at 19:00 to account for time zone differences. Testing covered three key areas – PLC communication software integration, full functional testing and full load testing, according to the company.

“As with any other witnessed FAT, the customer was provided with a comprehensive results report by WEG,” Spohr said. “This enabled the customer to check, in exactly the same way, that the remote FAT results were within the required tolerances.”

Spohr noted that this pioneering step is likely to influence the way these tests are done in future.
“It has shown that the testing can be done to the same standards, but with significant savings in time and cost,” he said.

Zest WEG companies supply DRDGOLD with electrics for Far West Gold Recoveries project

WEG Automation Africa and WEG Transformers Africa, part of the Zest WEG Group, have 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, in South Africa.

The gold tailings recovery project will see 500,000 t/mth 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, said 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, according to Willemse.

“At the tailings facility, the customer required a medium voltage substation, a low voltage substation and a control room,” Willemse said. “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 m pillars elevating the structure to allow optimal visibility from the control room, according to the company. Heat losses were factored into the design to ensure the substation remained cool and the installation was fitted with a fire detection system.

Willemse said an important consideration was to reduce the footprint of the substation, with free-standing VSDs allowing 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 said. 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 1,600 kVA transformers and the tailings MCC is fed by one 1,600 kVA transformer; both were manufactured at WEG Transformers Africa’s Wadeville facility.

Stuart Brown, Sales Team Leader at WEG Transformers Africa, said: “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. 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, according to the company. This will translate, over time, into energy savings for the customer, and is an important advantage, according to Brown.

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 a 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,” the company said. “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 to facilitate a 50 kA fault level, WEG moulded case circuit breakers, 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, the company said. 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.

aluzinc simplifies and speeds up Shaw Controls’ MCC manufacturing process

The replacement of steel by aluzinc in the manufacture of Shaw Controls motor control centres (MCCs) has brought with it a range of benefits, Shaw’s Senior Manager Operations, Anderson Kohler, says.

“Traditionally, we used only steel for our MCCs, which needs to be powder coated in order to protect it from corrosion,” Kohler said. “This made it necessary to follow quite a long process in completing our products – a process which aluzinc can now simplify and speed up.”

The usual process of preparing MCC panels includes welding, grinding and prewashing before the powder coating painting process can take place. These phases can now be bypassed by using aluzinc; a material that resists corrosion without a protective coating being applied.

Kohler highlighted the extended lifespan of aluzinc, which comprises 55% aluminium, 43.5% zinc and 1.5% silicon – manufacturers of the product guarantee it will last for about 35 years before any major maintenance is required.

He said the powder coating of steel panels complicates the earthing requirement on an MCC, as the paint layer insulates the panel and prevents conductivity. “This means that technicians and installers must take special care to ensure that proper contact is made between the unit and the earth connection,” he said.

For instance, the use of star washers must be strictly enforced among installation staff. Alternatively, certain areas of the MCCs are left unpainted to allow for earth connections. This does raise the concern that it only takes a small oversight and the earthing will not be fully effective, Kohler pointed out. The use of aluzinc eliminates this issue as there is no longer a paint layer between the earth connection and MCC panel, he said.

Shaw Controls said: “There is also the possibility of painted parts being scratched or damaged during transport and installation. When this occurs, it leads to the time consuming task of being returned to the factory for proper powder-coating, further delaying the installation and commissioning process. Indeed, if there is a need to weld again for any reason, then there is a repeat process of grinding and pre-washing before painting again.”

Kohler said the corrosion-resistant properties of aluzinc allowed parts to be kept in stock, ready for quick assembly; something not possible with mild steel due to corrosion.

“By introducing the use of aluzinc in the manufacture of our MCCs, we can reduce the lead time on components by as much as two to three weeks, and this is a time-saving that we can pass on to our customers by delivering more quickly,” he said.

There are also environmental benefits to using aluzinc as a replacement, said Kohler. No welding means a saving on gas and electricity, for instance, while no pre-washing obviates the need for harsh chemicals. In the painting process, there is invariably waste created through surplus paint that must be carefully disposed of in terms of environmental regulations.

Shaw Controls, a Zest WEG company, has over 30 years’ experience as a manufacturer of MCCs, distribution boards, medium voltage switchgear, control desks, PLC and instrumentation enclosures, portable and containerised substations, E-Houses and various other electrical enclosures.