Lapp GmbH Kabelwerke is a leading provider of cables, leads, and cable accessories. By implementing state-of-the-art system technology in a retroﬁ t, the company achieved a considerable increase in cable production efﬁ ciency while saving energy at the same time.
If a plant is past its prime, a decision must be made as to whether to have it retroﬁ tted or buy a new one. Lapp GmbH Kabelwerke, based in Stuttgart, Germany, decided on a retrofit for one of its plants, and Ritter GmbH of Mühlacker modernized all the electrical and control technology.
Increase in efﬁ ciency of up to 20 percent
Lapp had started to systematically modernize the machines for the production of electric cables at its manufacturing facility several years ago. “The mechanical parts of our machines are so strong that we merely need to modernize the electrical and control technology to bring them up to the state of the art,” says Martin Hallmen, who is responsible for new processes and machinery investments at Lapp. One of the plants that has already been retrofitted is referred to as Aderstrasse (or “Lead Street”) 7. It owes its name to the fact that highly ﬂ exible, coated leads are produced in this 30 mlong plant. In the course of the retroﬁ t, the plan was not only to modernize the technology but to increase performance and efﬁ ciency at the same time. “Among other things, we wanted to achieve an increase in ef-ﬁ ciency between 10 and 20 percent,” explains Joachim Meyer, the authorized representative of Ritter who was responsible for the modernization.
Precise heating and cooling control
Saving electricity is the top priority for our retroﬁ t,” emphasizes Hallmen. The choice of industrial controls shows that great store was set on that not only in the case of the six servodrives but also on the small scale. “Quality consistency was also very important to us,” he continues. With better controls and more precise servo technology in the drives, the company was able to implement this consistency. In addition, solid-state switching devices and cooler blowers on the extruders were integrated for exact temperature control. The Sirius 3RF23 zero-point switching solid-state contactor allows the heating circuits to be quickly switched on and off. “In addition to the zero-point switching devices, we are also using an instantaneous version of the solid-state contactor,” says Christoph Meyer, who is responsible for the electrical engineering department at Ritter. Thus, cooler blowers on both extruders can be switched directly. Such devices are suitable because the switch-on frequency is very high here. The more precise the control, the better the power and production efﬁ ciency of the cable manufacture. For the direct starter of the AC asynchronous motor, Lapp decided to use feeders consisting of Sirius 3RV2 circuit breakers for motor protection and Sirius 3RT2 contactors. The latter have an electronic coil control that reduces their power loss by up to 92 percent.
Greater ﬂ exibility thanks to PC-based hardware
Another signiﬁ cant goal of the retroﬁ t was a reduction in production costs. “Thanks to the improved control technology, we are now able to adapt the cable diameter much more precisely to the speciﬁ cations and thus use up to 10 percent less plastic per order,” explains Hallmen. The control technology, the heart of which consists of a powerful embedded industrial PC, the Simatic IPC427C Microbox PC, is also responsible for this. The real-time- capable Simatic WinAC RTX controller for PCs installed on it replaces the PLC used previously. The corresponding interfaces allow the easy integration of Industrial Ethernet, Profinet, and Profibus to the Microbox PC. The inverter and the I/O units within the application are integrated by means of Proﬁ net. The Simatic ET 200M distributed I/O system and the even more compact ET 200S version are used as interface modules to the central control. “This way we achieve control transparency, which allows us to provide remote service without any problems,” says Georg Goll, a software expert at Ritter. The application is operated via a ﬂ at-panel monitor.
A completely successful retroﬁt
With the modernization of Aderstrasse 7, Ritter demonstrated the beneﬁ ts of a systematic replacement of switching technology, control technology, and drive engineering. The family-run business implemented an integrated retro-ﬁ t from switching technology to visualization. “It is extremely beneficial to obtain everything, from switching to control technology, from a one-stop shop,” concludes Joachim Meyer. In the case of Aderstrasse 7, this included both the distributed I/O system and PCbased control. In addition, all the components were perfectly synchronized in accordance with Totally Integrated Automation (TIA). That suited Lapp very well, as Hallmen emphasizes: “The retroﬁ t was based on a strategic plan so that other plants worldwide can bene-ﬁ t from our modernization efforts and optimize their processes. We are inviting everyone to be a part of it.