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Automation Technology

Two become one

A global leader in the manufacture of compressed air systems based in Coburg in the Upper Franconia region of Germany deploys LOGO! in conjunction with the KNX fieldbus in many areas of the building control and utility supply systems for its factories. Thanks to the easy migration of an energy-saving lighting control to the high-performance latest-generation LOGO!, in one of the production facilities the number of base units has now been halved from two to just one using a KNX module.

Kaeser Kompressoren SE, Coburg, Germany - Founded in 1919, today employs more than 5,000 people worldwide – with just under 2,000 of them in Germany. The company’s product portfolio covers the full spectrum of compressed air generation, conditioning, and distribution. The growing family-owned business successfully markets its highly reliable, economical, and energy-efficient products and related services through branch offices and exclusive partners in more than 100 countries. Production facilities are in Germany, at sites in Coburg and Gera. Two new production buildings and an additional administration building are currently under construction at the company’s headquarters location in Coburg.

The company has a long-standing sys­­tem partnership with Siemens. “We particularly like the standardization, compatibility, and almost unlimited combinability of the solutions. We use a wide variety of Siemens products in our utility supply and building control systems, from transformers to KNX modules,” explains Stefan Gruber, head of Kaeser’s electrical infrastructure and systems technology department. He cites further benefits: “We can obtain all the electrical components we need from a single source; we can rely on expert advice and sup­port in all areas; and long-term worldwide availability of replacement parts for the products is assured.”

Lighting as and when needed

Gruber operates about 100 LOGO! units in his department alone, mostly in combination with KNX, as a flexible and convenient bridge, as it were, be­tween the KNX world and the conventional world. “It is something that has developed over many years,” reports KNX Manager, Christian Pohley, who programmed his first LOGO! way back in 1999, in the second year of his apprenticeship at Kaeser. “Back then it was used to switch the lights on and off in different factory areas, as well as providing a central switch-off function, controlled by buttons on a panel. Today, our lighting control with LOGO! is more diversified, and we use it in multiple buildings.”

In the distribution center, for example, until recently two Logo! 0BA7 units connected to a KNX module switched the fluorescent ceiling lighting – grouped by area – in three separate phases: “Brightness sensors detect how much light is falling from the outside onto specific points in the logistics center precalculated by us,” says Gruber. “The light strips beneath the ceiling are divided into thirds, and if more light comes in from outside LOGO! switches off one-third of the overhead lights in the area concerned, then a second third in the next phase. With this solution we save around 25% on our electricity bill for lighting. With KNX alone, that could only have been done at much greater expense and effort.” The final third of the light strips provide the basic lighting that always stays on.

The LOGO! and KNX module no longer have to be installed in the same place, ­because the new module has network capability and is a stand-alone unit.
Christian Pohley, Kaeser Kompressoren

Migration in two hours

The migration to the new LOGO! 8 with the new LOGO! CMK 2000 KNX module took Pohley just two hours. “Of course, my many years of experience helped,” he says. “Drag-and-drop programming is very easy and has not changed essentially since the early days. But the best thing is that I now need only one unit instead of two. The reduction was possible because with the new KNX module I am able to configure the 50 communication objects via KNX, freely and independent of the analog and digital inputs and outputs – even with a maximum number of LOGO! hardware modules.” Another benefit: “The LOGO! and KNX module no longer have to be installed in the same place, because the new module has network capability and is a stand-alone unit. And that adds flexibility too: I can deploy the module where it’s most useful at any given time.”

Based on this positive experience, Pohley will also be controlling the light­ing in the two new production buildings in Coburg with the LOGO! 8. And he is also looking to install the likewise energy-saving ventilation and shading control that is already in use at the Gera plant. “There the LOGO! operates as a timer – again at an un­beatably low cost,” he says. “It receives the DCF [German longwave time signal] from the weather station on the roof via KNX, and I have programmed it so that, depending on the season, it opens and closes the blinds and the windows at specific times of day.”

From fault signaling to gate control

Kaeser Kompressoren uses low-cost, user-friendly, space-saving LOGO! solutions in many other areas – with and without KNX. Applications include signaling for nonsafety and system-related faults, such as in heating and ventilation. They are logged by LOGO! for maintenance purposes and sent via KNX to the home server, which then in turn sends e-mail or SMS text messages to the appropriate personnel. 

To enable the security officer at the main site to open and close the entry and exit gates of the remote location known as the Mobilair works from a KNX panel, Pohley installed a LOGO! 0BA7 unit at each location and connected them over the company’s Ethernet network. Kaeser also uses LOGO! for intelligent ­control of the two pumps in an effluent pumping station and to monitor and signal the fill levels of tank installations, as well as on numerous models, such as one for a turnstile gate (see photo below) in the company’s own training workshop.

Picture credits: Kaeser