They began the search for a product that was, above all, reliable. In the past Control Techniques, an Emerson business, provided Freudenberg with a 1.4 MW drive solution. It is also the sole supplier of parallel inverter modules which provide the resilience needed in the production of nonwoven textiles.
However, the challenge was more demanding; Freudenberg was seeking the most efficient solution possible with the ability to physically fit the drive in an extremely limited space.
Also, as the incumbent solution was now out of production, parts for were becoming hard to find. It was also of concern that, from an energy consumption perspective, the existing solution was expensive to run.
Having bought from Emerson before, Freudenberg had a high level of confidence in the products and engineering support.
As part of their multi-source policy and to ensure that they got the best solution at the best price, Freudenberg evaluated the AC Drive offerings of a number of suppliers. Ultimately, the need for a small footprint drove them to the only viable solution – a free standing Unidrive SP AC drive from Emerson.
The Unidrive SP free standing drives are up to 50% smaller and are significantly lighter than other compact drive enclosures, making it an excellent choice in applications like Freudenberg’s where space is at a premium.
The Unidrive SP8434 is the most powerful drive in the size 8 enclosure. With an input range of 380-480 V, the SP8434 provides a maximum current of 620 A, with a typical output power of 355 kW – all in a compact footprint of just 800mm x 600mm.
To save further space, Freudenberg selected the incomer option where the circuit breaker is built-in at the factory. This meant that the drive was delivered to site ready to be connected, thus reducing engineering effort and installation time. The circuit breaker was fitted into a 400mm wide enclosure within the small footprint, 2209mm high unit. Even with the addition of the incomer option the SP8434 weighed only 751lbs (340.6kg) allowing the unit to be moved into the available space with ease.
In parallel with upgrading the AC drive, Freudenberg also installed a new motor with greater capacity. As a result of the new solution, a significantly higher process performance can be delivered and less energy is used, meaning Freudenberg achieves greater production capacity and significantly lower running costs.
Even though size, reliability and efficiency were the primary criteria in selecting the Unidrive SP8434, there were a number of other features that were important to the engineering team at Freudenberg. Modularity was one such feature, along with the ease of implementation and starting-up of the drive.
The CTSoft drive configuration PC tool allowed Freudenberg to commission the drive using configuration wizards. Settings can be read, saved and loaded using the Smartcard and the learning curve was simple, thanks to the ability to visualize and modify the configuration using live animated diagrams.
Alongside the CTSoft configuration package, Emerson also provided its CTScope package. CTScope is a fully featured software oscilloscope used for viewing and analyzing live values within the drive. The user interface is based on a traditional oscilloscope, so Freudenberg’s engineering team found it very intuitive to use in Kaiserslautern, helping them commission the drive more quickly.
Freudenberg found Emerson’s technical support highly knowledgeable but, more importantly, accessible; whenever the engineers had a question, high quality support was available to guide them through the commissioning process.
As a result of this successful retrofit, Control Techniques drives are now the leading choice for future retrofits at Freudenberg Performance Materials in Kaiserslautern. The business is also considering the introduction of LSRPM permanent magnet synchronous motors from Leroy-Somer to create even greater energy savings.
Commenting on the experience with Emerson, Hans Schneider, electrical machine builder at Freudenberg, Kaiserslautern said “Reliability, performance and efficiency are critical for us at Freudenberg. With the Unidrive SP8434 we found all three of these things in a product that would fit in the limited space available to us.
The installed software and support made installation easy for our team and we can move forward with greater production capacity at a lower cost, safe in the knowledge that spares are readily available. I am confident in Emerson and I expect we will use them for future projects of this type.”