18 Integrated systems for the <strong>new</strong> machinery directive Ever faster, ever more productive, ever stronger. That, in a nutshell, is the current trend in handling technology and logistics. The <strong>new</strong> European Machinery Directive is intended to ensure that safety doesn’t get a raw deal. Klug GmbH integrierte Systeme has come up with a mechatronic solution that ensures safety in compliance with the directive but with no loss of convenience and at com- parable costs. And the 9400 servo drives from Lenze play a central role.
The storage and retrieval units used in logistics systems operate at speeds of up to six metres per second. Ambros Kienberger is convinced that “To operate with such dynamics as safely as possible, a uniform safety concept is needed”. He is in charge of handling the logistics projects for which Klug is the general contractor. The 9400 Servo Drives are an essential component within the control system. They are integrated via a PROFIBUS connection with the PROFIsafe protocol. Future Ethernet standards can also be integrated. The interplay of mechatronic elements As the Klug company explains, successful safety solutions are best achieved with mechatronic systems. “The perfect interplay of software, electronics, drive controllers, and electromechanics with the motor, including the feedback system, is crucial”, emphasises Michael Weiherer, director of automation technology at Klug. The intensive project work with Lenze was guided by three primary objectives: to achieve a higher level of safety to protect the machines and their human operators in accordance with the EU standard, to maintain ease of operation, and to achieve these objectives at comparable costs. The solution that was implemented and approved by the inspection association TÜV Süd is a pathbreaking one. “Thanks to the farsighted teamwork with Lenze, we now have a tested and comprehensive safety standard that can be applied across all industries”, Kienberger says with evident satisfaction. “If we take the level of automation as the benchmark, safety engineering with the Machinery Directive is now just catching up technologically and conceptually”, Michael Weiherer adds. Because systems or machine modules are being driven ever more frequently to their physical performance limits, “worst case studies are unavoidable.” Always under control The primary purpose of all safety functions is to safely limit the motion of the drive on command or in the event of an error. The stop functions are therefore among the most important. According to the situation, the drive is shut down – in the form of the “safe torque off” function (STO), with which the energy supply to the motor is safely interrupted. The 9400 servo drives provide this function with the SM100 safety module fitted in the drive controller. The yellow module is inserted in a slot reserved for safety equipment. The sensors are then connected directly to the safety module. If more extensive safety functions are required, the functionally more highly scaled SM301 module is used. With this, for example, the speeds and positions of the travelling and hoist drives in storage and retrieval units can be safely recorded and monitored. Integrating the safety functions into the drive controller offers many advantages over conventional solutions. “Drive-based safety” gives greater clarity to the form in which the safety technology is implemented, and it simplifies the system <strong>structure</strong>. One of the positive cost aspects is the avoidance of external components (safety switch, speed monitor, guards, or a second sensor system for “safely limited speed”). From a functional point of view, the faster shutdown on command or in the event of an error means an increase in safety, since no points of separation with contacts are required. Because the safety technology provides status information available in the servo inverter and, therefore, in the PLC, there is also an improvement in the diagnostic possibilities. Securing competitive advantages The Klug example proves that real competitive advantages can be achieved with innovative solutions in the context of the <strong>new</strong> machinery directive. Those who are quick to adapt to the <strong>new</strong> directive will have an easier time of marketing their systems in Europe. If unpleasant surprises are to be avoided during commissionings in 2010 and beyond, it makes sense to begin working with drive specialists as early as in the planning phase. For this reason, Lenze is actively helping to implement and interpret the directive within the associations VDMA (Verband Deutscher Maschinen- und Anlagenbau e. V.; German Engineering Association) and ZVEI (Zentralverband Elektrotechnik- und Elektronikindustrie e. V.; Central Association of the German Electrical and Electronics Industry). “We are involved and always up to date particularly in the classification of drives in the application areas ‘components/modules’ or ‘incomplete machines’”, emphasises engineer Martin Grosse, product manager for safety engineering at Lenze. New machinery directive As of 28 December 2009, the <strong>new</strong> Machinery Directive 2006/42/ EU applies to all machines, replacement equipment, safety components, load handling devices, chains, cables and lifting belts, removable cardan shafts, incomplete machines and construction site lifts for people and/or goods. Once a machine has been built, the machine manufacturer is responsible for certifying that it is in compliance with the directive’s requirements by attaching the CE mark to it. The <strong>new</strong> Machinery Directive 2006/42/EU does not introduce any sweeping changes but does change a large number of details and in the Declaration of Conformity. Its scope of application has been more clearly defined, particularly by separating it from the Low Voltage Directive and including construction site lifts and load handling devices, which previously were mentioned only in Appendix I. on the job 19
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