Ensure sound knowledge of international standards and guidelines
national committees, the International Electrotechnical Commission (IEC) is the leading standards organization in the electrotechnical area. Many countries around the world have their own national versions of the IEC standards.
Always up to date with SiemensJust as the technology is always being refined, the relevant standards and Directives governing control panels are also subject to regular updates: a revised version of IEC 60204-1 (Electrical Equipment of Machines) was published in late 2016. New EU Directives were transposed into national legislation before the end of 2016. We always advise you in real time of important new developments and their impact on your day-to-day activities.
IEC standards describe the state of the artIEC standards are applied in about two-thirds of countries world-wide. Designers and builders of control panels who apply the relevant IEC standards and document the fact can be confident they are satisfying market requirements in most countries.
Important IEC standards
Delimitation of IEC 60204-1 and IEC 61439-1/2
Because of growing uncertainty on the market as to which standard should be considered most important for a machine control panel, the German Commission for Electrical, Electronic and Information Technologies of DIN and VDE (DKE) has published a statement on this subject.
Various standards have to be observed for the construction of control panels for machinery. IEC 60204-1 is the relevant standard, but it is the manufacturer's responsibility to ensure the best possible electrical safety of the control panel.
This is why we recommend that a risk analysis be carried out. For the European market, this is even stipulated in the relevant directives. If further risks are identified during the risk analysis that, in the opinion of the manufacturer, are not covered by IEC 60204-1, then IEC 61439-1/-2 and, if necessary, other standards may also be consulted as an additional design aid. The DKE (Deutsche Kommission Elektrotechnik Elektronik Informationstechnik/German Commission for Electrical, Electronic & Information Technologies) has also published a recommendation in this regard.
Basic safety standard IEC 60204-1, “Electrical equipment of machinery – Part 1: General requirements for the electrical equipment of machines” constitutes an important standard for control panels as part of a machine.
Scope of IEC 60204-1
- Applies to the use of electronic equipment and systems for machines
- Starts at the point of connection to the electrical equipment of the machine
- Relates to control panels with rated voltages of up to 1,000 V AC or 1,500 V DC
Outlook: Revision of IEC 60204-1
In recent years, the International Electrotechnical Commission worked on a new version of IEC 60204, which was published in late 2016. It is expected that national standards will be derived from this from late 2017 onward. The new standard has not yet been incorporated in the Official Journal of the European Union.
The new version mainly involved the revision or introduction of the following topics:
- Applications with drive systems
- EMC, surge protection, short-circuit rating and protective conductor system
- Control circuits and control functions
- Symbols for actuators and control devices
- Requirements for technical documentation
- National requirements, normative conditions and references to the literature
IEC 61439 is the standard for low-voltage switchgear and controlgear assemblies and, following a transitional period, has had sole validity since 2014. Parts 1 and 2 establish safety requirements for power switchgear and controlgear assemblies, which may also be of relevance to machine control panels.
Requirements in the European Economic Area
EU Directives set forth the product requirements that apply throughout Europe. Products marketed in the European Economic Area must satisfy the protection goals of the applicable Directive or Directives.
The essential Directives governing control panels for machines are the Low Voltage Directive 2014/35/EU and the EMC Directive 2014/30/EU. The Directives refer in turn to harmonized EN standards, which in most cases are borrowed from the IEC standards.
No sales without a CE mark
The CE mark is a legally prescribed label for all products that comply with EU Directives, and is thus essentially a “technical passport” for products within the European Economic Area. The EU declaration of conformity forms the basis for CE labeling of a product: it is the manufacturer’s declaration that the product it is marketing complies with the fundamental health and safety requirements of all relevant European Directives, i.e. that it is in conformity with them.
The CE mark must be applied directly to the product. If this is not possible on technical grounds, the packaging and/or accompanying documentation (instructions for use, certificate of warranty) may also be used for the CE mark.
April 20, 2016: Eight new EU Directives came into force
Starting in 2008, EU Directives have been standardized as part of the New Legislative Framework (NLF). On April 20, 2016, the new versions of a total of eight EU Directives were transposed into national legislation of the EU member countries, including the Low Voltage, EMC and ATEX Directives.
- Documentation must be available in a language that is understood by local authorities and users
- Documentation must include a risk analysis and assessment
- A postal address must be included on the product itself or, if this is not possible, on the packaging or the enclosed documentation.
- A clear definition of the economic operators and their obligations: manufacturers, authorized representatives, importers, distributors
- A clear definition of the following activities:
- Making a product available to the market
- Conformity assessments
- Withdrawal from sale
The Low Voltage Directive stipulates the following safety objectives:
- The essential characteristics for safe use must be specified
- Electrical equipment shall be made in such a way as to ensure it can be safely and properly assembled and connected
- Electrical equipment shall be so designed and manufactured as to ensure that protection is assured against the hazards listed. Definition of one stipulation for equipment maintenance is permitted
Protection against hazards arising from the electrical equipment
- Persons and domestic animals are adequately protected against the danger of physical injury or other harm that might be caused by direct or indirect contact
- Temperatures, arcs or radiation that would cause a danger are not produced
- Persons, domestic animals and property are adequately protected against non-electrical dangers caused by the electrical equipment which are revealed by experience
- The insulation is suitable for foreseeable conditions
Protection against hazards which may be caused by external influences on the electrical equipment
- Meets the expected mechanical requirements in such a way that persons, domestic animals and property are not endangered
- Is resistant to non-mechanical influences in expected environmental conditions, in such a way that persons, domestic animals and property are not endangered
- Does not endanger persons, domestic animals and property in foreseeable conditions of overload.
- The scope of application was extended to include domestic animals and objects. It also covers other hazards (mechanical, chemical; noise, etc.)
Essential EU Directives for control panels and machines
It’s essential to identify the right Directive in each case, since this will affect the standard to be applied and the cost and effort required for the declaration of conformity and documentation.
The following EU Directives may be of relevance to control panels and machines:
Save time when selecting, laying out and dimensioning our globally certified products. Use our tools to arrange the technical features of products and systems, easily and intuitively, to suit the requirements of your application.
Create standards-compliant control panel designs
The safe, efficient and convenient examination of heat in compliance with the standards is a major challenge in planning and building a control panel. The legal and normative requirements not only have to be taken into account but also added to the documentation for an industrial control panel as part of a technical risk assessment. The same applies to electromagnetic compatibility.
Dealing with short circuits
Consideration of short-circuit capability is fundamental to building a safe control panel. That’s why the expected minimum and maximum short-circuit current at the machine’s infeed (RMS value in kA) must be agreed upon between the customer and machine manufacturer.
SIMARIS design planning tool
With the SIMARIS design software, you draw up a grid calculation, including a calculation of short-circuit current, based on real products with a minimum number of inputs – by calculating the medium voltage up to the power outlet. In addition to grid calculation, the software also calculates short-circuit current, load flow, voltage drops and energy balance.
The standard for electrical equipment of machines does not include proof of short-circuit.
All it states is that:
- The rated shut-down power for short circuits in surge protection devices must be greater than or equal to the fault current expected at the place of installation, and
- The wire must be laid out to take the short-circuit current into account
Calculate let-through current quickly and easily using the SIMARIS curves design planning tool
Proof of rated short-circuit currents as per IEC 61439-1 may be provided as follows:
Comparison against a reference design (check-list or calculation)
There is no need to demonstrate the short-circuit capability of electrical circuits in the following cases:
- Switchgear and controlgear assemblies with a rated short-time withstand current Icw or rated conditional short-time current Icc not exceeding 10 kA RMS;
- For auxiliary circuits: UN ≥ 110 V, PN ≤ 10 kVA and uk ≥ 4%, UN < 110 V, PN ≤ 1.6 kVA and uk ≥ 4%
- Switchgear and controlgear assemblies or switchgear/controlgear assembly circuits, protected by current-limiting devices with a let-through current not exceeding 17 kA at the maximum permitted uninfluenced short-circuit current at the infeeds to the switchgear and controlgear assembly
Use our overview of let-through values for this, e.g. for circuit-breakers and fuses.
Both international standards and European Directives contain rules on documentation. We provide a general overview of the requirements and our tools help ensure easy, time-saving implementation.
The information needed for setting up, operating and maintaining the electrical equipment within a machine must be supplied in appropriate versions according to IEC 60204. The information must be provided in an agreed language.
The customer documentation must contain the following elements:
A comprehensive description of the equipment
Operating manual, maintenance manual
- Notes on assembly / installation / connection to power supply
- Where applicable, details on the physical environment, schematic circuit diagram, programming, inspection intervals, etc.
- Wiring diagram
- Description of protective devices (locked functions for machines that operate together in coordination, etc.)
- Technical protective measures
- Information on handling, transportation and storage
According to IEC 61439-1, the technical documentation must include all identifying features of the switchgear and controlgear assembly.
These include the following:
- Rated values for voltages, e.g. rated voltage of the switchgear and controlgear assembly, rated voltage of switchgear/controlgear assembly circuits, and rated insulation voltage
- Rated current values (InA, Inc, Ipk, Icw, Icc)
- Rated diversity factor RDF (also for groups of circuits)
- Rated frequency fn
- Contamination level, protection type (IP code)
- System based on earth connection (network type)
- Breakdown by EMC (environmental condition A or B)
- Type of short-circuit protective device(s)
- Electric shock protection
- Total dimensions, mass, etc.
The customer documentation as per IEC 61439-1/2 also contains the following:
- Notes on transportation, handling, setup, operation and maintenance
- Device, part and circuit identification (parts list, layout drawing, circuit diagram, terminal diagram)
Technical documentation must be written in a language that can be easily understood in the target country. It must be kept available for the authorities for ten years after the electrical equipment was last placed on the market.
The technical documents must contain at least the following elements:
- General description
- Conceptual design and manufacturing drawings and schemes, circuit diagrams, etc.
- Descriptions and explanations thereof, also for operation of the electrical equipment
- List of the associated standards applied or description of the measures taken to comply with the safety requirements
- Results of design calculations, examinations carried out and test reports (of the manufacturer or of third parties)
- Copy of the declaration of conformity
- Suitable risk analysis and assessment
Risk analysis and assessment
A suitable risk analysis and assessment is part of the conformity assessment procedure. This is necessary in addition to a risk analysis and assessment that may be conducted, if applicable, within the scope of the Machinery Directive.
“Reasonably foreseeable” operating errors must also be considered during the assessment procedure.
To perform the risk analysis within the scope of the Directive, the European Committee for Electrotechnical Standardization (CENELEC) offers the CENELEC Guide 32 as guidance for safety related risk assessment and risk reduction for low voltage equipment.
Powerful tools to draw up documentation efficiently
Many small steps are involved in drawing up documentation. Looking for documents, finding and compiling them is often a time-consuming and complex task. Our tools make it possible to draw up the documentation in parallel with the engineering process.
Documentation included – our practical planning tools
Our tools not only help with standards-compliant product selection, dimensioning and layout of your control panel: many outputs and reports can also be used as supporting materials for your documentation. For example, you can use:
- SIMARIS therm to demonstrate temperature rise limits
- SIMARIS curves to demonstrate short circuits
Much of the data that is needed for documentation in compliance with standards and Directives can be downloaded using the CAx Download Manager. Just enter the article numbers for the Siemens products from your parts list and you can get all the available product data in a single package:
- Certificates (e.g. EC declaration of conformity)
- Data sheets
- Characteristic curves
- Operating instructions and manuals
White paper changes for power drive systems
Changes the new IEC 60204-1 brings for power drive systems
The new edition of IEC 60204-1, which is used as a reference for the electrical safety of machinery and industrial control panels, also contains technical changes for applications involving power drive systems, e.g. the safe standstill of drives. Find out how these changes are applied in practice in our compact white paper.