Electricity and Control January 2021

DRIVES, MOTORS + SWITCHGEAR

At a glance  Bandag SA has been providing a much-needed truck tyre retread service to the African logistics industry since the 1960s.  The automated mixing machine, which breaks down rubber and other constituents into working-compound batches, entails an energy-intensive process requiring consistent speeds and considerable force.  The installation of ControlTechniques’ Unidrive M700 ac drives has helped the plant achieve energy savings and reduce downtime.

The retread manufacturing facility in Alrode, Johannesburg, starts with the processing of raw material. applications. Two Unidrive M700 drives are connected to a common gearbox which shares the load throughout op- eration. “We are proud to say that Jim has been using our Control Techniques range of drives for many of his customers in the tyre industry. We have developed a close partnership and ensure that we give him the best service and value, which he can carry through to his end-users.” Grobler adds. Ready for the future The drives were each rated at 750 kW but scoped up to 1 MW to cater for future use. “We upscaled the project for future developments – the motor, the transformer, and the drive panel. It is designed so we can slot in an extra mod- ule, so it really is future-proofed,” says Fraser. A greener solution Control Techniques’ UnidriveM series is designed to en- hance the energy efficiency of all applications and David is pleased to report that the plant has seen a monthly energy saving of about 10% since the technology was deployed. As well as saving money, this contributes to a lower carbon footprint – a key concern in the logistics industry. The drives feature low power standby mode, and the dc bus configu- ration enables breaking energy to be recycled within the drive system. Additionally, the drives’ magnet motors offer exceptional efficiency across all operating speeds. Less downtime As well as the energy savings, the plant has seen higher production efficiencies since the new system was installed. “After troubleshooting and overcoming our ‘teething phase’, we now easily achieve five percent more uptime and we have improved production by about six percent on certain compounds since upgrading to the Unidrive M700 series,” says David. “This is really a significant benefit to our sustainability as a business. The retread market in South Africa is huge, and if we can deliver our product at high volumes, consistently and on time, it means great things for our market share.” And it is good news for the Bandag SA Johannesburg plant, which employs 70 people, and for the 75 people employed in the adjoining head office.

Operations continue through extruding, pressing, finishing, trimming, quality control and warehousing.

Plant visualisation Alongside the drives’ performance, the increased uptime can also be attributed to the increased data visibility offered by the system. Insights into drive health and energy use are easily visible using the plant’s dis- tributed control system, contributing to clear plant visualisation. A unique project Grobler highlights various aspects of this project that stand out. “Most significantly, it involved a world first for Control Techniques, which we were proud to be a part of,” he says. “At the time of installation, this intermeshing mixer was the biggest tangential drive that Control Techniques had done.” David remarks, “We were the Guinea pigs! The biggest worldwide tandum drive system at the time was 500 kW. At the Bandag plant we had two of 1 MW each.” This illustrates Multispeed Transmissions’ appetite for a challenge and the capabilities of Control Techniques’ high-performance drives, and makes it clear why Bandag SA has con- tinued to work with them. David notes too: “In addition to the technological solution, one fac- tor that has contributed to the success of this project is that it has gone far beyond installation. Throughout our operation, Jim and his team are at hand to assist us, with the support of Bruce and Control Techniques. If an issue arises, we can call Jim who ensures that some- one is onsite to assist us that same day, with spare parts at hand from Control Techniques. No excuses are made. Spare parts are acquired and available as soon as we need them, so if a breakdown does occur, we get running again as soon as possible.” This service level ensures convenience for the customer and the benefits of saving space and costs of warehousing and carrying spares. “For 20 years we have trusted Jim, and we will continue this professional relationship into the future,” David concludes. □

For more information visit: www.nidecautomation.com / www.controltechniques.com

Electricity + Control JANUARY 2021

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