Tectra Automation recently supplied Bosch Rexroth frequency converters to two Gauteng companies aiming to reduce their energy consumption and operational expenditure through more efficient, on-demand motor performance.

With electric motors the single biggest consumers of power within industrial automation, more and more companies are implementing measures to overcome the costly peaks in consumption that can increase the electrical cost of that unit by up to seven times its operating current.

One such company is a packaging manufacturer in Industria, Johannesburg. Tectra Automation supplied a 160 kW Type Fe frequency converter in November 2014, to drive the company’s 75-kW air compressor in an open loop.

“Analysing the pre- and post- readings we received from the site’s power monitor demonstrated that the plant had shed over 100 KVA of its power load during normal operation after we had installed the frequency converters,” explains Georg Venter, Product Manager, Tectra Automation.

This was a relatively straight-forward installation that merely drove the motor connected to a pressure switch. A second company, a steel producer in Kliprivier, Gauteng, acquired an additional pneumatic component to drive its 30 kW air compressor.

“We supplied a pressure transducer in a closed loop circuit that will provide even greater efficiency in the way the motor is used. It accurately responds to the requirements of the accumulator proportionally, relative to the pressure inside of the accumulator,” Venter explains. “The pressure transducer, from our range of Aventics pneumatic components, is part of our turnkey drive solutions for air compressors.”

Tectra Automation deliberately oversized the electrical panel it had built for this customer, as the company plans to fit a second VSD for their second compressor at a future date.

In addition to curtailing the sudden power spikes associated with overcoming motor inertia, the frequency converters also reduce the mechanical stress exerted within the system, thus prolonging the life of the affected mechanical components.

Bosch Rexroth frequency converters Type FE for motors from 750 W to 160 kW, distributed in sub-Saharan Africa by Tectra Automation, a Hytec Group Company, provide a simple, accurate and reliable three-phase drive control solution for asynchronous AC motors.