broad changes to 60204-1 Edition 6

Author: Andreas Beyer | Last edited: 10.07.2020

The new 6th Edition of the basic safety standard IEC 60204-1 with the title "Safety of machinery - Electrical equipment of machines - Part 1: General requirements for electrical equipment of machines" came into force on June 1, 2019. A transition period applies here until 14.09.2021. The current edition deepens many of the basic safety requirements. Some chapters, such as 'Documentation', have been completely revised. Informative appendices for project planning (Appendix B) as well as (Appendix I) regarding the technical documentation have been added.

4 General requirements

Within chapter 4.2.2 a reference to the IEC 61439, as well as to Annex F, has been included. This means that IEC 61439 may be applied in whole or in part for a switch-gear and control-gear assembly. An important addition is that EMC immunity and emission tests become mandatory, insofar as the electrical components used do not already meet the relevant EMC requirements and the installation and wiring of these components has been carried out in accordance with the operating instructions of the respective manufacturer. In addition, there is the necessary check of the ambient conditions. Therefore, the electrical components must be examined for vibration, shock and impact resistance for the intended loads, and the altitude of the future place of use must be taken into account.

Chapter 4.4.2 Electromagnetic compatibility (EMC) has been rephrased.

5 Requirements for 'Devices for disconnecting and switching off

Requirements for 'Devices for interrupting the power supply to prevent accidental start-up' have been added. From now on the 'mains disconnection device' can take over this function. This includes, for example, the possibility of preventing 'restarting' by using a suitable padlock.

Chapter 5.2

¨Terminal for connection to the external protective earthing system¨ has been renamed into ¨Terminal for connection of the external protective conductor¨ and the cross reference to 8.2.2 has been deleted referring to aluminum conductor

Chapter 5.3.4

Chapter 5.5

the therm ¨disconnecting¨ in reference to plugs has been replaced by isolation.

6 Protection against electric shock

The term ¨protection against direct contact¨ has been replaced by ¨basic protection¨ & the term ¨protection against indirect contact¨ has been replaced by ¨fault protection¨. This is due to adaptations in international language use and also shows adaptations to the use of terms in the North American market.

7.10 Short-circuit current rating - NEW

One of the most important changes with regard to system documentation is the mandatory specification of the rated short-circuit current of all electrical equipment. Various methods are shown for determining this value. Both the application of design rules and calculations or Type tests are permitted.
However, a verification is only required if the rated short-time withstand current (Icw) at the bus-bar or in the case of the switch-gear the short-circuit current (Icc) at the installation site is higher than (10kA eff ) or (Id) of current limiting devices (17kA peak value).

10.7.3 User interface - Disconnection device operate emergency stop

The current edition of the standard now stipulates that an interruption of the power supply by the mains disconnection device to activate the stop function (e.g. of a frequency inverter) can be assumed as 'Stop category 0'. Thus, this new definition allows to stop a movement while it is in 'emergency stop' mode.

11 Switchgear and controlgear assemblies

From now on, when installing switch-gear, heat calculations and the preparation of a thermal balance will be required. The aim is to avoid overheating during operation of the machine. A possible method of calculation here is the verification according to IEC 61439. While switch-gear combinations with a rated system current (> 1,600A) according to IEC 61439 must always be tested, for rated currents of (≤630A) a calculation according to the so-called (RDF method) is common.

Chapter 11.5
¨Access to control-gear electrical equipment¨ description has been replaced by cross-reference to IEC 60364 Low-voltage electrical installations Part 7-729 Requirements for special installations or locations - Operating or maintenance gangways

13.1.4 AC circuits – Electromagnetic effects (prevention of eddy currents)

This chapter has been added with cross -reference to IEC 60364 Low-voltage electrical installations - Part 5-52: Selection and erection of electrical equipment - Wiring systems

Chapter 13.2.2 has been clarified; symbolic added

Chapter 13.5.2 ¨Wiring outside enclosure - Percentage fill of ducts¨ has been removed

The 1st paragraph in chapter 13.5.2 ¨rigid metal conduit fittings¨ been rephrased

15.1 Residual current devices (RCDs) for socket-outlets

The exception for PELV circuits has been removed. Residual current devices (RCDs), which were previously (optionally) required for socket outlets up to 20A, must now generally be protected with a rated differential current (IΔn ≤ 30mA).

16.4 Marking of enclosures of electrical equipment

This chapter has been revised. The following information should be provided as a minimum.

17.2 Technical documentation

A comprehensive revision of the technical documentation was carried out. Reference is made to the necessary documents which a manufacturer is obliged to produce for his machine. This documentation must cover the entire life cycle of the machine. A new Annex I (informative) gives assistance here.

18 Verification

This section has been revised and chapter 18.1 now reference to Type-C standards. General verification requirements are now referring to...

... of continuity of the protective bonding circuit (test 1 of 18.2.2)

... that the 8.2.6 ¨requirements for electrical equipment having earth leakage currents higher than 10mA¨ are met

... function for RCDs in accordance with manufacturers instruction. The test procedure and test interval shall be specified in the maintenance manual.

Table 10 - Examples of maximum cable lengths from protective devices to their loads for TN-systems has been added.

18.2.3 Testing - Power Drive Systems

The condition for protection by automatic disconnection of the power supply in the event of a fault must now be verified. It must be ensured that a fault results in a shutdown of the faulty circuit if a frequency converter or servo drive is installed. If the inverter itself does not include a suitable protective device, an external protective device must perform this task. The fault loop impedance must also be checked to ensure that the assigned protective device responds properly in the event of a fault.

Annex

Annex D.5 ¨Effect of harmonic currents on balanced three-phase systems¨ & Annex H ¨Measures to reduce the effects of electromagnetic influences¨ have been added.

Conclusion

The basic safety standard EN 60204-1:2018 is listed in the Official Journal (April 2020) of the Machinery Directive 2006/42/EC and is binding for machines. The electrical equipment can be supplemented by components according to IEC 61439, but the exclusive application of IEC 61439 is not sufficient with regard to the safety of machines.

Many corrections have been made within the standard with the latest edition. However, the important changes that have been made to be implemented by the machine builders are manageable. Anyone who has previously been designing and implementing in accordance to standards should not face much new challenges in the revised EN 60204-1 Edition 6.