Knowing how its done

The consistent application of standards and guidelines as a basis for safe and efficient control panel manufacturing

Schaltschrankbau, Author Carolin Meuschel

Products that are perfectly adapted to each other significantly simplify planning and implementation for control panel manufacturers. But ultimately the device hardware alone is not all that is critical. The necessary expertise to fulfil standards and comply with new directives is also indispensable. Data integration, clever tools, and simple document generation also help optimize the engineering process in control panel manufacturing and increase efficiency.

Electrical technology is constantly changing, a fact that builders of control panels deal with in their daily work. One example of such changes are the new EU directives that take effect from April 20, 2016.

Implementing the new EU directive – a challenge

The transition period from the previous EU directives to the new directives ends on April 20, 2016. That is why the consistent implementation of the new directives, oriented on the New Legislative Framework (NLF), represents a challenge for control panel manufacturers. Eight new directives are affected, among others the Low-Voltage Directive, the ATEX Directive (explosive atmospheres) and the EMC directive governing electromagnetic compatibility. These directives in particular require the close attention of control panel manufacturers, as they are relevant for countless electronics products, and nearly every electronic product with an operational voltage from 50 to 1,000 volts (AC) and 75 to 1,500 volts DC, which means they apply to complete control panels as well. The aim of the NLF, which led to the modernization of the directives, is to unify and increase precision in EC Regulation 765/2008 with regard to terminology, placing products on the market, more precise identification of manufacturers, importers, and dealers, as well as strengthening market monitoring. The latter will result in more clearly formulated product requirements.

Important changes to EU directives from April 2016

One essential aspect of the new EU directives is in the area of declarations of conformity. Starting in 2016, directives call for just one declaration of conformity per product. This declaration will then cover all of the applicable directives. Products that fall under the ATEX or Measuring Instruments Directive must be delivered with the declaration; the Low-Voltage Directive leaves this open. Siemens makes declarations of conformity for its devices available on the internet via the CAx Download Manager, for instance. That makes it convenient to download the declarations with other product-related data, such as drawings, measurements, pictures, and technical data for use in CAD and CAE systems. Using this support tool saves up to 80 percent of the time needed for the overall engineering process and helps control panel manufacturers comprehensively meet the documentation requirement.

Increasing documentation requirements

What will be introduced over the coming year in the new EU directive has already been established in another area. The EN (IEC) 60439 standard underwent a radical revision and restructuring a few years ago, for instance. For approximately the past year, the new EN (IEC) 61439 standard for low-voltage switchgear and controlgear assemblies is applicable exclusively. With this change in standards, the requirements were more clearly formulated. At the same time, control panel manufacturers were subject to new obligations with regard to verification and documentation. In particular, gaining design verification with regard to short-circuit resistance requires a certain degree of effort in practice. That is why Siemens provides short-circuit values, for instance for the Sentron 3VA molded case circuit breaker, the circuit breakers from the Sirius modular system, and for our comprehensive portfolio of fuses.

To ensure that control panel manufacturers are always on the safe side, the automation supplier also makes a contribution to fulfillment of these and other standards beyond its products. In workshops and individual consultations the company provides information on what European directives and standards should be taken into account when designing and building control panels and control cabinets. In addition to practical design tips, participants find out which standards and directives apply, and under what circumstances. For instance, the Siemens experts offer recommendations as to which standard is best applied to machine control panels, the above-mentioned EN IEC 61439-1/2 (low-voltage switchgear and controlgear) or EN (IEC) 60204-1 (safety of machinery).

In the increasingly globalized world, control panel manufacturers are confronted more and more with having to serve markets outside Europe. This is particularly difficult when compliance with North American standards is required, which sometimes differ significantly from IEC standards. Examples are UL 508A from Underwriters Laboratories (UL), NFPA 79 from the National Fire Protection Association (NFPA) or requirements of the Canadian Standards Association (CSA). Companies interested in exporting to the USA need to have an understanding of these standards and regulations in order to commission their machines there without any problems. Frequently, little things can mean the difference between “Run” and “Stop”. It is an added benefit when component manufacturers not only offer products certified according to domestic standards, but are also able to provide information about how to use the products in conformity with applicable standards. For several years, Siemens experts have offered training courses and comprehensive documentation in this area. One popular reference is the “Industrial Control Panels for North America” guide, which serves as an aid to practical applications and is available for download on the internet.

Modern drive technology is changing control panel engineering

The high-efficiency IE3 motors which became mandatory for mains operation throughout the EU in 2015 show just how much it pays to have a partner well versed in standards. As an automation supplier Siemens had been testing the different starting behavior of IE3 motors from a diverse range of manufacturers for years prior to the requirement taking effect. In the process, testers not only used theoretical extrapolations, but also measured values for numerous motors in test series. As a consequence, Siemens’ controls were optimized to ensure that both the switching and protective functions were suitable for the previous and newest motor generations. Control panel builders can therefore be confident when using products from the Sirius modular system that short-circuit protection has been optimized so that “normal” behavior can be differentiated from “fault” behavior in the so-called inrush current to motors.

More efficiency through data at the press of a button

This example demonstrates that comprehensive knowledge from the device manufacturer is becoming noticeably more important, whether from a technical or standards perspective. As a partner for control panel manufacturing, Siemens does not see itself merely as a purveyor of standards and product knowledge. “In our workshops and consultations we also learn a lot about our customers’ processes in control panel engineering,” says Martin Berger, an application consultant for North American and IEC standards at Siemens. He adds, “We also get all sorts of suggestions about how we can improve our products even more. Of course, we pass this information on to our colleagues in product management. After all, ultimately our highest goal is to help our customers master their day-to-day challenges in the best way possible.” Berger sees increasing cost and time pressure as the principle challenges. “Anything that makes the process more efficient helps our customers save time and money.”

That is why, when introducing new products, Siemens makes a conscious effort to save customers’ time spent on selecting products. One of the ways it does this is by offering online configuration tools that let customers conveniently and intuitively select from among a raft of innovations and accessories. One good example is the Sirius Act pushbuttons and indicator lights range; another is the 3VA molded case circuit breaker. Once a variant or even a whole shopping cart full of products has been selected, mechanical automation and electrical engineers have access to comprehensive data at the press of a button without having to perform time-consuming searches. The data can be incorporated into any standard planning or design tool – yet another step toward greater efficiency.

With the supplier’s knowledge, always up to date

Siemens supports control panel manufacturers in all sorts of ways – whether with products, system solutions, or with expertise, services and software tools. The critical issue is meeting applicable standards/regulations. Siemens makes the required modifications to its products at an early stage and offers compact knowledge resources for a broad range of needs, along with support in the form of training, workshops, online help, and software tools. This sets users up for success in mastering changes in control panel engineering and ensures the development of economical, high-performance electronics.

Eight new EU directives in the framework of the NLF, from April 20, 2016

  • 2014/28/EU (Explosives for Civil Uses): Previously 93/15/EEC
  • 2014/29/EU (Simple Pressure Vessels): Previously 2009/105/EEC
  • 2014/30/EU (Electromagnetic Compatibility): Previously 2004/108/EEC
  • 2014/31/EU (Non-Automatic Weighing Instruments): Previously 90/384/EEC
  • 2014/32/EU (Measuring Instruments): Previously 2004/22/EEC
  • 2014/33/EU (Lifts): Previously 95/16/EEC
  • 2014/34/EU (ATEX): Previously 94/9/EEC
  • 2014/35/EU (Low-Voltage Directive): Previously 2006/95/EEC

Essential manufacturer obligations of the new EU directives

  • Generation and retention of “technical documentation,” including a “risk analysis and assessment”
  • Conformity assessment, declaration of conformity, CE label
  • Suitable passive and active market observation in case of danger to consumers (if necessary, spot checks in market)
  • Product identification labels
  • Manufacturer name and address
  • Provision of required safety information in “understandable language”
  • In case of hazards: Inform the responsible authorities, appropriate correctional measures up to recall, if necessary