Drives, motors + switchgear: Products + services
One drive, ten motors: rethinking medium-voltage motor control
and mechanical stress that typically plague traditional motor starting methods. In practical terms, the benefits are substantial, says van Wyk. So¡er acceleration reduces torsional stress on sha¡s, couplings and driven equipment, in turn extending asset life and reducing maintenance costs. Pressure surges are avoided in continuous processes such as pipeline compression and fans and pumps experience fewer process upsets and less unplanned downtime. Overall, this contributes to significant energy savings for equipment driven by the variable speed drive. Fewer assets, lower lifecycle costs By consolidating motor starts into a single drive system, industrial organisations can reduce capital and operating expenditure significantly. In some applications, customers have reported up to 80% fewer drives required compared to traditional systems. As well as lowering upfront costs, reducing the number of drives simplifies maintenance and spares management. It creates a cleaner, more manageable automation environment with intelligence built in. Additionally, the PowerFlex 6000T with Synchronous Transfer Bypass integrates into various modern digital architectures through networked connectivity, enabling direct communication with control systems. This connectivity supports predictive maintenance, enhanced diagnostics and improved visibility into motor and process performance. Operational resilience and flexibility The PowerFlex 6000T with Synchronous Transfer Bypass features dedicated variable-frequency drive input and output cabinets, individual per-motor bypass sections (which also serve as emergency direct online starters should they be required), line reactors and controls, all coordinated through a centralised control system. This design enables secure, seamless handover between variable-speed and fixed-frequency operation via dedicated buses. It supports a highly resilient motor control system that protects the process and the equipment. Well suited to mining, water, wastewater, oil and gas, concentrated solar plants and utility infrastructure industries, the PowerFlex 6000T with Synchronous Transfer Bypass is designed to perform in the most demanding industrial environments.
For South African industries facing rising energy costs, constrained capital budgets and increasing pressure to improve uptime – a review of how they start, control and protect large motors in their plants can make a dierence. Adrian van Wyk, CEO of Referro Systems, says a new approach to medium-voltage motor control allows several high-power motors to be managed using a single medium-voltage variable speed drive. This delivers significant reductions in capital expenditure, footprint and system complexity, without compromising reliability. Referro Systems, as a local distribution partner for Rockwell Automation, has introduced the PowerFlex® 6000 medium-voltage ac drive with Synchronous Transfer Bypass (STB) for use in mining, water, utilities and heavy-processing operations across South Africa. According to van Wyk, the solution represents a step change in medium-voltage motor control design, particularly for sites that have a number of large motors operating in unison. Conventional medium-voltage motor control systems typically rely on individual drives or starters for each motor. Although eective, this approach can be capital intensive, space consuming and complex to maintain – especially in applications such as pumps and fans, where motors are o¡en started one at a time rather than simultaneously. The PowerFlex 6000T with Synchronous Transfer Bypass addresses this challenge by enabling up to 10 motors to be started and synchronised across the supply line using a single medium-voltage drive. The system supports combined currents of up to 3 000 A, with a maximum of 680 A per motor, across voltage ranges from 2.3 kV to 11 kV. Once any motor in the system reaches operating speed it is synchronised to the fixed-frequency bus, and the drive is automatically freed to start the next motor in sequence, should the process require this. This architecture reduces the number of variable speed drives required across a site yet still delivers all the benefits of variable speed control during continuous speed requirements – smooth start-up, acceleration and deceleration control delivered by one variable speed drive. Smoother starts, longer equipment life The Synchronous Transfer Bypass technology is core to the solution. It ensures that voltage, frequency and phase are precisely matched during the transfer from variable-frequency operation to fixed-speed operation and vice-versa. The synchronous transfer enables a smooth, bumpless transfer. It eliminates the inrush current spikes, voltage dips Continued from page 11 Senior operators and technicians carefully supervised testing and li¡ing procedures, ensuring compliance with industry standards and regulations. Compliance with various testing standards – established by the International Electrotechnical Commission (IEC) and M&C’s internal standards – was maintained throughout the project. Eective coordination with the customer was maintained by compiling weekly progress reports and holding regular meetings that adhered to the outlined project timeline.
For more information visit: www.referro.co.za
Notably, the customer engaged an independent third-party specialist to verify and sign o on all hold points, further enhancing the project’s transparency and credibility. M&C’s dedication to quality workmanship and customer satisfaction is unwavering. It extends the lifespan of these 15 MW machines successfully and, as an expert in this field, it oers repair solutions for customers.
For more information visit: www.mandc.co.za/
12 Electricity + Control MAY 2026
Made with FlippingBook flipbook maker