Last edit: 07/08/2023
THE QUESTION
Machine and control panel manufacturers often wonder which Electrical Standard shall they follow for the CE Marking of Industrial Control Panels.
There are different schools of thought: some people think that the IEC 60204-1 Safety of machinery – Electrical equipment of machines – Part 1: General requirements is the only one applicable standard, and others think that IEC 61439-2 Low-voltage switchgear and controlgear assemblies – Part 2: Power switchgear and controlgear assemblies is fully applicable as well.
CONSIDERATIONS
The doubt is justifiable because neither of the two Standards could be classified as the Product Standard for the industrial control panels.
IEC 61439-2 is the standard for low-voltage switchgears, while IEC 60204-1 provides requirements and recommendations related to the electrical equipment of machines so as to guarantee:
– Safety of persons and property;
– Consistency of control response;
– Ease of maintenance.
IEC 60204-1 is more an installation Standard than a product Standard, equivalent to NFPA 79 for the USA market. The IEC 61439-2 is the product standard closer to the concept of industrial control panels despite the Standard is written having switchgears in mind.
In the USA the situation is clear: the product standard for switchgears is UL 891, and the one for industrial control panel is UL 508A.
But let’s look at the language used in the two standards.
In the current edition of IEC 61439-2 we find the following language:
This part of the IEC 61439 defines the specific requirements of power switchgear and controlgear assemblies as follows:
– Assemblies for which the rated voltage does not exceed 1000 V in case of a.c. or 1500 V in case of d.c.;
– Stationary or movable assemblies with or without enclosure;
– Assemblies intended for use in connection with the generation, transmission, distribution and conversion of electrical energy and for the control of electric energy consuming equipment;
– Assemblies designed for use under special service conditions, for example in ships and in rail vehicles provided that the other relevant specific requirements are complied with;
– Assemblies designed for electrical equipment of machines. Supplementary requirements for assemblies forming part of a machine are covered by the IEC 60204 series.
It is clear that the object of the standard extends to Industrial Control Panels and that IEC 60204-1 provides “supplementary requirements”.
However, in the new edition of IEC 61439-2, published in May 2020, the last paragraph was removed to clarify that IEC 60204-1 is the reference standard for control panels. However the manufacture can follow the prescriptions from IEC 61439-2 which provides supplementary requirements. Similar approach was done for IEC 61439-1, published in July 2020. Both standards are not applicable to Industrial Control Panels anymore. That means, from the moment the new edition of the standards will be harmonised to the Low Voltage Directive, it will only be up to the panel manufacturer's, based upon the risk assessement, to decide which parts of EN 61439-1/2 to follow.
That is in line with what is stated in the 2018 edition of EN 60204-1 (or 2016 edition of IEC 60204-1):
In addition to the requirements of IEC 60204-1, depending upon the machine, its intended use and its electrical equipment, the designer may select parts of the electrical equipment of the machine that are in compliance with relevant parts of the IEC 61439 series.
That meas, for example, that for an Industrial Control Panel with 25 A main switch, the manufacturer could easily follow the requirements of IEC 60204-1 only.
In case of a machinery control panel with a 1000 A main switch, the designer should follow, in addition to the requirements of IEC 60204-1, also some of the requirements of IEC 61439-2, relevant to its application.
CONCLUSION
Ultimately, the Machinery (or industrial control panel) manufacturer shall always follow the requirements provided by IEC 60204-1, but he should comply with the requirements of IEC 61439-2 that he considers applicable to its specific application. We remind that the CE marking of the machine is a self-declaration, which however relies on a sincere risk assessement made by the manufacturer.