IEC 62368-1 safety standard

There is a quite new electrical safety standard you need to know: IEC 62368-1. If you are working with electronics design, you need to notify this new standard. IEC 62368 is an entirely new product safety concept: it isn’t a merger of existing standards, but it does cover the older standards IEC 60065 and IEC 60950, which will be replaced in due time. It is a hazard-based, performance-oriented standard. The end goal is the design and manufacture of safe products by using it.

Historically, ICT (Information and Communication Technology) and AV (Audio/Visual) equipment have been regarded as separate products and markets. 30 years ago, it was pretty easy to discern what was an Audio/Visual (AV) product and what was a computer (IT). At that time it made sense to have different safety standards for them: EN 60950-1 for computers and EN 60065-1 for audio/video.

The world has changed so that the line between “traditional” AV devices and IT equipment has become very blurry: for example your tablet computer is as much computer as it audio/video device. For this reason IEC decided to develop a new “hazard-based” standard would cover both electronic equipment and IT/Communications technology. The result wasIEC 62368-1, Audio/video, information and communication technology equipment – Part 1: Safety requirements. This new standard would cover both electronic equipment and IT/Communications technology. The IEC 62368-1 is intended to be more generic and technology independent than previous standards.

IEC 62368-1:2018 is applicable to the safety of electrical and electronic equipment within the field of audio, video, information and communication technology, and business and office machines with a rated voltage not exceeding 600 V (includes equipment rated 400/690V). The standard also apply to external power supply units and other accessories intended to supply other equipment within the scope of this part of IEC 62368 (but not motor-generator sets, battery backup systems and distribution transformers)

This document does not include requirements for performance or functional characteristics of equipment. It is basically a product safety standard that classifies energy sources, prescribes safeguards against those energy sources, and provides guidance on the application of, and requirements for, those safeguards. The prescribed safeguards are intended to reduce the likelihood of pain, injury and, in the case of fire, property damage.

The new 62368-1 has a completely new structure and assumes a new hazard-based approach. This new approach is based on the premise that damage can occur when energy of sufficient strength and duration influences a body. The consideration of the risk caused by possible sources of energy is the most important point for safe device design. Risk assessments are carried out in nearly all industry sectors with a risk potential or in which technical products can cause risks during operation. The risk assessment in general analyzes what can go wrong, how likely it is to happen, what the potential consequences are, and how tolerable the identified risk is.

In December 2020, the new IEC/EN 62368-1 will replace the existing safety standards EN 60950-1 and EN 60065-1. The date of withdrawal (DoW) for the outgoing standards IEC 60950-1 and IEC 60065 is December 20, 2020. In Europe the outgoing standards will be withdrawn in
favour of the new EN 62368-1 standard, and so presumptions of conformity with directives that reference the old standards will also cease
. It means that EN 62368 will become mandatory under the requirements of the LVD and the RED.

Fortunately in most cases you don’t need to do very much or redesign all your products. There are so many similarities on the demands of the new and older standards, that if your product is already tested and certified according EN 60950-1 or EN 60065-1, in most cases it is possible to update to the new EN 62368-1 with a few Delta Tests. Manufacturers, who are in the development phase and plan to place their products on the market from December 2020 onwards, must follow the new standard.

What is the next after the new electrical safety standard? Is there more coming to safety as software is eating hardware?

It seems that nowadays in many cases the safety of products goes beyond the physical layer, as mishaps in software performance can cause serious safety risks. In essence, this means that there are now two types of safety: basic safety and something we call functional safety.

Basic safety is what we define as freedom from unacceptable risk caused by physical hazards (fire, electric shock, environmental damage) as a result of a product’s physical construction or design.

However, what if that new software on the smoke detector stalls or crashes? That could seriously hinder its functioning. In other words: how safe is a product when something fails? In this respect, we see that traditional product safety is moving from a focus on the hardware to a focus on the (embedded) software.

Safety standards that include requirements for functional safety such as IEC 60730 ANNEX H (electronic controls for household use) were developed to cater to the need of electronics that increasingly perform safety-related functions, like the lock on your oven door. The mother standard of functional safety requirements is the IEC 61508 which provides the framework for many sector and application-specific functional safety standards.

 

15 Comments

  1. Tomi Engdahl says:

    IEC 62368-1: An Introduction to the New Safety Standard for ICT and AV Equipment
    The established safety standards for ICT (60950-1) and AV equipment (60065) are to be phased out in favor of a single standard, 62368-1. What does the new standard mean for product certification, and how can OEMs best manage the transition?
    https://www.electronicdesign.com/resources/white-paper/whitepaper/21143135/iec-623681-an-introduction-to-the-new-safety-standard-for-ict-and-av-equipment

    Reply
  2. Tomi Engdahl says:

    Oikean virtalähteen valinta on tärkeää uuden kuluttajatuotteita koskevan IEC/UL IEC-62368 -standardin turvallisuusvaatimusten täyttämiseksi
    https://www.digikey.fi/fi/articles/the-right-power-supply-to-meet-the-new-iec-ul-iec-62368-safety-mandate

    Reply
  3. Tomi Engdahl says:

    New safety standard IEC 62368-1 replacing IEC 60950-1 and IEC 60065
    https://www.mascot.no/blog/archive/new-safety-standard-iec-62368-1-replacing-iec-60950-1-and-iec-60065/

    Within just a year or so, manufacturers of ICT and AV equipment will have to conform to a new standard for product safety, the IEC 62368-1.

    The date of withdrawal (DoW) for the outgoing standards IEC 60950-1 and IEC 60065 is December 20, 2020.

    There are a few things one should have in mind, not least when dealing with power supplies, as Part 1 of the standard deals with safety requirements. IEC 62368-1 was written using hazard-based concepts, with energy sources and their potential harmful effects as focal design considerations.

    The standard which has been published in its 3. edition, IEC 62368-1:2018, is applicable to the safety of electrical and electronic equipment within the field of audio, video, information and communication technology, and business and office machines with a rated voltage not exceeding 600 V (includes equipment rated 400/690V).

    This does not include requirements for performance or functional characteristics of equipment. It is basically a product safety standard that classifies energy sources, prescribes safeguards against those energy sources, and provides guidance on the application of, and requirements for, those safeguards. The prescribed safeguards are intended to reduce the likelihood of pain, injury and, in the case of fire, property damage. This 3. edition cancels and replaces the second edition published in 2014.

    The standard also apply to external power supply units and other accessories intended to supply other equipment within the scope of this part of IEC 62368.
    This part of IEC 62368 does not apply to power supply systems which are not an integral part of the equipment, such as motor-generator sets, battery backup systems and distribution transformers.

    Reply
  4. Tomi Engdahl says:

    https://incompliancemag.com/article/iec-62368-1-what-can-we-expect/

    In October 2018, the International Electrotechnical Commission (IEC ) published Edition No. 3 of IEC 62368‑1, further merging the safety requirements for audio/video, information and communication technology equipment. IEC 62368‑1 Edition 3 differs from Edition 2 in a number of areas, as follows:

    Addition of requirements for outdoor equipment;
    New requirements for optical radiation;
    Addition of requirements for insulating liquids;
    Addition of requirements for work cells;
    Addition of requirements for wireless power transmitters;
    Addition of requirements for fully insulated winding wire (FIW);
    Alternative method for determination of top, bottom and side openings for fire enclosures; and
    Alternative requirements for sound pressure.

    It appears that the acceptance of components such as power supplies that were previously certified under IEC 60950‑1 will also be allowed under the 3rd Edition of the standard. That means that, since all new submittals in North America must be done in accordance with UL/CSA 62368‑1 as of December 2020, existing component recognitions can be continued with just minor changes.

    Currently the enforcement date for the 3rd Edition is to be determined. Also, as of December 2020, all new evaluations for IEC certification will be conducted in accordance with the requirements of IEC 62368‑1. One of the possible issues facing manufacturers who ship products globally after December 2020 is that if, for example, they have to have a CB report in order to sell their products into countries that have not adopted IEC 62368-1, they may be required to obtain a dual CB report. i.e., a CB report based on IEC 62368-1 to sell in Europe and other countries that have adopted the new standard, and another CB report for the same product based on IEC 60950-1 or IEC 60065 for regions that have not adopted IEC 62368-1. This means extra effort and extra cost for the manufacturers.

    Reply
  5. Tomi Engdahl says:

    https://electricalconnection.com.au/new-energy-classifications/

    For the different energy sources, the following would appear to hold true:
    ES1 classification

    ES1 classification is when either the touch current limit or the touch voltage limit is considered safe for an ordinary person to touch.

    ES2 classification

    ES2 classification is applicable when ES1 conditions have not been met, however is still either touch current limited or touch voltage limited but is a higher level than ES1.
    ES2 is considered to be safe with basic safeguards.
    100W Power over Ethernet (PoE) and HBase T would be considered to fall under ES2 classification.

    ES3 classification

    ES3 classification is applicable when ES2 conditions have not been met.
    ES3 circuits have no voltage and no circuit current limit.
    ES3 is classified as hazardous and requires basic and supplemental safeguards to protect ordinary persons.

    Reply
  6. Tomi Engdahl says:

    Nov 12’th : 2018: EPSMA TC MeetingMunich – GermanyDave Collins – Applications Engineer :IM&DNorthern [email protected] 62368-1 Introduction
    http://www.epsma.org/Dave%20-%20IEC62368-1%20-%20EPSMA-Nov%202018%20%20M-M.pdf

    Reply
  7. Tomi Engdahl says:

    The established safety standards for ICT equipment (60950-1) and AV equipment (60065) are to be phased out in favor of a single standard, 62368-1, in North America and the EU. The new standard introduces a different, hazard-based philosophy to product testing.

    A Shift to Hazard Based Safety Engineering
    https://www.cui.com/iec-62368-1-power-supplies

    IEC 62368-1 is an international safety standard that applies to electronic equipment designed for information and communication technology (ICT) and audio-visual (AV) applications. It combines and replaces the long-standing IEC 60950 (ITE applications) and IEC 60065 (AV applications) standards. The standard approaches product safety differently than those it replaced by applying the principles of Hazard Based Safety Engineering (HBSE), which uses a three-block model to identify hazards and determine appropriate safeguards.

    Reply
  8. Tomi Engdahl says:

    Power 101: IEC 60335-1 Explained
    https://www.cui.com/resources/resource-library/power-101–iec-60335-1-explained

    In this Power 101 video we dive into IEC 60335-1, the safety standard for household appliances. With the evolution of IoT and smart devices, household appliances now have wireless connectivity, graphical displays, and other features commonly associated with ITE applications. Learn more as we compare key differences between IEC 60335-1 and the ubiquitous IEC 60950-1.

    Reply
  9. Tomi Engdahl says:

    IEC 62368-1: Global safety standard applies to a wide
    range of electrical and electronic equipment up to 600 V
    https://info.littelfuse.com/hubfs/LFUS_CES_IEC62368-1_Spotlight.pdf?utm_campaign=ESBU%20-%20Spotlight%20Emails&utm_medium=email&_hsmi=199423951&_hsenc=p2ANqtz-_FaW6Bk0ZXChHdzl6k6ZIQ07zSRqdM8NbWFIn6e_KT10zGrgJqmGZifPD00lLhu1x__UeideEstLw9wSYvQ1FS56-B4567CQqfecvl1JugOCCapTQ&utm_content=199423951&utm_source=hs_email

    Minimum transient voltage withstand rating
    is determined by the AC mains voltage

    PCs, routers, notebooks, tablets, and their power supplies
    fall within Overvoltage Category II

    Table 12 in section 5.4 specifies the following: 120 VAC
    power supplies will need to withstand 1500 Vpk; 240 VAC
    power supplies need to withstand 2500 Vpk

    Reply
  10. Tomi Engdahl says:

    Understanding the IEC 62368-1 standard for electronic equipment
    https://www.electronicproducts.com/understanding-the-iec-62368-1-standard-for-electronic-equipment/?utm_medium=email&_hsmi=210586222&_hsenc=p2ANqtz-91vi0uDqbQ5lvTVpgKs7sVK4aoIONCrfeKSGw4FanIClwulg4gSRdE2YoNKCq87zw4e7M-e00jywXvbMFIzokzR-Ddqm2RYkO2jB1Y1rWfKOjq5qU&utm_content=210493540&utm_source=hs_email

    Applying the IEC 62368-1 standard to universal power adapters requires careful consideration of overcurrent and surge protection devices.

    The regulation of power-based products and components is critical for design development and user safety. For decades, the International Electrotechnical Commission (IEC) has dictated how to design information technology equipment and audio/video products for safety. The IEC’s traditional approach to equipment safety has been product-dependent and incident-based, making the previous standards, IEC 60950-1(information and communication technology equipment) and IEC 60065 (audio and video equipment), more reactive and less adaptable to emerging technologies.

    A new regulation, IEC 62368-1, became the single default standard on December 20, 2020. Thus, designers no longer can choose to comply with either the information/communication technology standard or the audio/video equipment standard. As the boundaries between information/communications and audio/video technology have blurred, the IEC 62368-1 hazards-based safety engineering standard applies to a broad scope of applications.

    The new standard is less product-specific. It focuses on the energy within the equipment and the intended environments. This future-proof approach aims to encourage manufacturers to address known hazards in the design and intended use of the product, whether its application is for industrial or residential use.

    Compliance testing

    AC line protection components help increase product reliability and must comply with specific tests required by IEC 62368-1. It is necessary to decide on the overvoltage category that applies to determine the parameters of some of the tests.

    Where the device connects to the electrical grid helps define the overvoltage category. The closer the proximity to the grid, the higher is the category and the hazard. For example, an electric meter on the outside of a house connected by a service wire to a transformer is considered Overvoltage Category IV. The electric breaker panel inside a home would be in a lower overvoltage category. Personal devices such as PCs, routers, notebooks, tablets, and related power supplies fall within Overvoltage Category II.

    Using the Overvoltage Category along with the line voltage, engineers can determine the voltage withstand rating. Power adapters connecting to 120-V outlets have a withstand voltage rating of 1500 V. For adapters connecting to 240-V outlets, the withstand voltage rating increases to 2500 V. This rating is an essential basis for component selection and applicable tests.

    The new standard also includes three tests related to varistors and gas discharge tubes (GDTs) for surge protection. The older standards did not have these tests. Varistors exposed to surge events can wear out over time, eventually becoming a hazard themselves. IEC 62368-1 now refers to a varistor as a possible ignition source, thus requiring additional tests.

    Choosing a compliant solution for universal power adapters

    Universal power adapters, commonly used in IT equipment, accept a wide range of voltage inputs, such as 90 to 240 VAC. This voltage range allows the product to be used worldwide with a common set of electronics. Safety requirements dictated by IEC 62368-1 require both overcurrent and surge protection.

    Overcurrent protection

    Selecting the correct fuse is critical to preventing damage from overcurrent events and passing fault testing. When choosing the right fuse, consider the following:

    The fuse should both achieve its purpose within the circuit and remain intact when the circuit is operating normally.
    The fuse must not nuisance trip. It must not open during either normal operations or surge pulse testing. To achieve this, calculate the predicted pulses’ energy and compare it to the fuse’s melting point. By targeting a proper ratio between the two values, engineers can be confident that the fuse will not nuisance trip during predictable pulses.
    The voltage rating of the fuse must be at least as large as the maximum rating of the power supply or system voltage.
    The fuse should have a maximum fault current rating higher than the maximum available fault current of the location where it will be used. This breaking capacity or interrupt rating determines how much current the fuse can safely interrupt.
    The fuse should fit in available space.
    The fuse must meet required third-party certifications, including UL or IEC requirements.

    Use these requirements to identify the best fuse for the application. For example, Littelfuse recommends its 3.15-A fuse in the 215 Series due to a high breaking capacity of 1500 A at 250 VAC.

    Surge protection

    There are several surge protection technologies available. Safety components include varistors, TVS diodes, protection thyristors, and GDTs.

    To determine the best solution for the application, engineers should first consider whether the ground is deemed to be reliable. Many home, office, and commercial spaces have unreliable ground connectors. Examples include wall sockets with a loose earth connector or a damaged ground terminal in the plug. Reliable ground connectors typically exist in industrial applications where the ground is hardwired or the equipment does not function without a good ground connection.

    For unreliable ground applications, IEC 62368-1 states that when using varistors in the common mode, connections between High and protective earth or between Neutral and protective earth, consider using varistors with a GDT as long as they comply with the Annex G.8 varistor overload test. For varistors used in the differential mode, High-to-Neutral, the varistors must meet all the criteria described in Annex G.8.

    To choose the right varistor, the minimum continuous operating voltage should be at least 1.25 times the maximum voltage rating of the equipment. Selecting the varistor’s required surge rating will determine the varistor’s diameter.

    For the universal power adapter example, a 300-V thermally-protected varistor can protect the line-to-line and line-to-neutral connections from voltage transients and lightning while meeting minimum surge requirements. Consider using a 3000-V GDT combined in series with a 300-V varistor in both line-to-ground and neutral-to-ground connections.

    While this is the most common surge protection solution for many electronic applications, designers can also consider other solutions. When comparing technologies, engineers should consider the component’s:

    Clamping voltage, which shows how well the device can protect during a surge event, with lower being better
    Let-through energy during a surge event, again, lower is better
    Leakage current
    Lifetime after multiple surge events
    Size and cost.

    IEC 62369-1 provides flexibility for safety requirements

    IEC 62369-1 introduces a new way to approach electronics product testing by requiring engineers to consider known hazards and use environments when designing a product. This hazards-based approach aims to keep pace with technological advances while giving product designers more flexibility within the framework.

    Reply
  11. Tomi Engdahl says:

    What National Certifications Does the Power Adapter Have, and What Are the Certification Marks of Countries Around the World?
    https://www.alrightpower.com/what-national-certifications-does-the-power-adapter-have-and-what-are-the-certification-marks-of-countries-around-the-world.html

    Reply

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