Tag Archives: WEG

WEG slip ring motors to drive milling operations at Vale Verde copper mine

WEG says it has supplied two M Mining slip ring motors to mining company Mineração Vale Verde to drive the main mill of a 4 Mt/y plant at its Serrote copper operation in Alagoas, Brazil.

The M Mining slip ring motors come with a power output of 5,400 kW and rated voltage of 13,800 V. They will be fitted to the FLSmidth-supplied plant

The WEG M Mining slip ring motor has a new automatic brush lifting system, which differentiates the WEG product from other motors on the market.

The motors were specially developed with electromechanical characteristics that provide durability, resistance and robustness, being able to operate in harsh environments like mine and cement sites.

In addition to the above advantages, M Mining line motors, with an automatic brush lifting system, incorporate operating logic, resources for fault investigation, monitoring of operation via HMI and prevention of improper manoeuvres, simplifying and reducing maintenance costs, motor installation, operation and maintenance, WEG says.

Vale Verde will be provided with technical assistance and WEG aftersales support, the company added.

Mineração Vale Verde said in early February that Serrote remained on track for first production in the second half of 2021. An August 2019 definitive feasibility study outlined a project able to produce around 20,000 t/y of copper-equivalent over an initial 14-year mine life from a low-strip, open pit mine supplying this 4.1 Mt/y processing plant.

WEG helps ventilate MMK’s Chertinskaya-Koksovaya mine in Russia

WEG Electric CIS, a subsidiary of WEG based in St Petersburg, has been awarded a contract to supply two flame-proof motors for the primary ventilation system of the Chertinskaya-Koksovaya mine in Russia.

Partnering with Ventprom, a manufacturer of underground ventilation equipment, WEG has developed unique, explosion-proof motors to meet the challenging conditions of a large-scale mining environment, it says.

The Chertinskaya-Koksovaya mine, in Belovo, is managed by MMK-Ugol, which produces around 3.4 Mt/y of coal, 2.8 Mt of which is used for steel production.

Working with Ventprom, WEG has designed a new motor that has been manufactured specifically to operate in this environment, it said.

Due to the nature of the Chertinskaya-Koksovaya environment, off-the-shelf motors would not suffice, according to WEG. To overcome this, WEG applied its expertise in motor design to develop a bespoke solution, with increased lifespan compared with more generic motors.

Using a tube-cooling design, WEG came up with two flame-proof motors that could operate effectively when fully enclosed. As opposed to air cooling, the motors minimise heat by using cooling tubes inside the motor’s frame.

As part of the commission, WEG also developed a unique bearing arrangement to endure the high loads and inertia of the application. The two flame-proof motors, which operated at an output of 2,400 kW, were customised specifically for deployment in the mining environment.

The two motors meet Customs Union certification, a standard for countries in the Commonwealth of Independent States. The motors also adhere to EACEx standards, the Eurasian conformity certification for explosion-proof products, according to WEG.

They were designed and manufactured for Chertinskaya-Koksovaya by WEG Portugal at one of the company’s European manufacturing facilities in Maia. The factory is one of two production sites in Portugal and specialises in the production of explosion-proof motors.

Ihor Sapa, Business Development of Russia and CIS countries at WEG Portugal, said: “Customised products are not necessarily a luxury, but a necessity in some sectors. For this project, developing a bespoke motor was essential. In the environment of the Chertinskaya-Koksovaya mine, the motors needed to be flame-proof and expertly designed.

“Thankfully, WEG Portugal is highly experienced in the manufacture of explosion-protected solutions.

“WEG’s customer-focused approach and the attention given to customers’ individual needs proves that WEG is prepared to address the requirements of unique and complicated projects – including underground mining and classified area products.”

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.

WEG looks to attract iron ore miners with latest slip-ring motors

WEG has unveiled its new M Mining series of slip-ring motors that, it says, are intended for dusty environments in the iron ore or cement sectors.

Available in frame sizes IEC 355 to IEC 1000, the new M Mining slip-ring motors cover the power range from 250 kW-10 MW at 50 Hz or 60 Hz line frequency. These three-phase induction motors are between four and 14 poles and designed for voltages up to 13.8 kV, making them a reliable choice for mills, crushers, blowers, exhaust fans, conveyors, centrifuges, and other applications in the mining and cement industries, it said.

Andreas Schulte Mesum, Director European High Voltage Solutions, based at WEG Germany GmbH, said: “Their performance and robustness make the new M Mining series of motors, with their high IP rating, steel casing and two different brush systems, an excellent choice for applications in the mining and cement industries. The design is based on specific electromechanical properties that offer long life and high stability.”

The wound rotors of slip ring motors allow them to achieve high starting torques along with low start-up current. In contrast to squirrel-cage motors, the windings are connected to three slip rings to allow a variable resistance to be inserted in the rotor circuit. This has several major benefits for users including higher rotor circuit resistance to improve the motor’s start-up characteristics; the motor starting current and rated current are close to the same; and loads with high starting torque can be driven, as well as loads with high inertia. Further advantages include higher efficiency and simple installation, WEG said.

The new motor series has a brush compartment with a new design and transparent window for inspection and access. Commissioning is aided by combining the motor with a fully integrated control panel as an option, according to the company. At the same time, operating and maintenance costs are reduced and plant availability is increased.

The motor series is available in two versions: either with a brush lifting device, or with brushes in constant contact. “The lifting mechanism of the brush lifting device has been redesigned to make it even easier to maintain,” WEG said. “Compared to the version with fixed brushes, the brush lifting system requires less maintenance. In addition, brush wear is reduced by fitted pressure springs. An integrated control system is also available as an option for the brush lifting device.”

With its innovative design and new insulation arrangement, the system offers other advantages.

“For example, the cooling system of the brush compartment is independent of the motor cooling system, further boosting the efficiency,” WEG said. “The extended lifetime of the brushes is one of the main advantages, but user access to the brush compartment is also significantly easier with this version. The brush compartment achieves an IP rating of up to IP66.”

The M Mining motors are available with protection ratings from IP55 to IP66. They are also protected by WEG paint systems that enable operation in abrasive and humid environments with atmospheric sulphur dioxide.

New WEG VSDs to help ventilate underground gold mine in Ghana

Two units of the newly developed WEG 11 kV Variable Speed Drive (VSD) have been commissioned at an underground gold mine in Ghana by WEG Automation Africa, a member of the Zest WEG Group, the company says.

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 VSD portfolio, and brings a range of benefits to customers.

“It gives WEG Automation Africa even greater flexibility in our market offering, further enhancing our capability to provide customised solutions,” he said.

The first two 11 kV units produced are for 850 kW ventilation fan motors in the underground gold mine in Ghana, according to the company.

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

Moss said: “The WEG MVW3000 is particularly suited to applications where there are standard motors with no special insulation 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, according to the company.

“The design includes power cells with long-life plastic capacitors, which are more reliable and last longer than dry type capacitors,” Moss 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 6,500 kW – although larger sizes are also available if required, the company said.

Among the options on the WEG MVW3000 is an automatic cell bypass solution. This ensures minimal reduction in the output-rated torque so normal operations can continue. Redundant power cells can also be added to the design to ensure 100% torque can be maintained.

Prior to delivery, all VSDs are fully load-tested in WEG’s facility in Brazil.