Get ready to evaluate safety measures in a different way.

JEFF SCHNABEL, CUI
THE FAMILIAR 60950-1 AND 60065 SAFETY STANDARDS for information and communication technology (ICT) and audio-visual (AV) equipment are being phased out in 2020, in favor of a single, harmonized standard based on a more modern approach to safety and testing. OEMs must act now to be sure their products are compliant by the deadline.

The new electrical safety standard IEC 62368-1 supersedes IEC 60950-1 and IEC 60065. Coordination between the North American and European certification bodies, UL/CSA and Cenelec, means regionalized 62368-1 standards will take over fully in each territory from December 20, 2020. Manufacturers producing products covered by 60950-1 or 60065 should be preparing now to handle the transition.

More widespread adoption of 62368-1 is ongoing. Authorities in Australia/New Zealand and Japan have already published their own equivalents, Mexico has introduced NMX-I-62368-1-NYCE-2015 on a voluntary basis, and bodies in China, Korea and South America are at the evaluation stage.

There are several drivers behind the move to the new standard. The outgoing 60950-1 and 60065 standards apply to ICT and AV equipment respectively, but the distinction between these two categories has become increasingly blurred as new technologies and new markets have developed. 62368-1 unifies and consolidates the two. Clause 1 of the documentation describes the scope of 62368-1, and Annex A presents a non-exhaustive list of product types covered. These include computers and networking products, consumer electronics, office equipment like copiers or shredders, telecom products and audio/video, information and communication technology.

However, the change goes beyond harmonization or consolidation. 62368-1 replaces the prescriptive approach common in older standards, which tend to specify safety features and the way they are implemented, in favor of Hazard-Based Safety Engineering (HBSE).

HBSE takes a performance-oriented approach that offers greater flexibility for standards-makers and designers, while also enhancing safety for end users. It lets manufacturers find innovative ways to ensure the safety of their products and at the same time relieves the need for frequent updating of the standard to keep pace with technological advances. Rewriting standards is expensive and time-consuming, and usually behind the curve of progress. In addition, the adoption of this approach is expected to minimize differences between regional or national interpretations of the IEC reference standards.

HBSE principles

As a safety-science discipline, HBSE has developed over the last 25 years and has shaped the content of standards such as ECMA-287 Safety of Electronic Equipment, which was published in 2002. The IEC Technical Committee, TC108, which created IEC 62368-1 and is also responsible for IEC 60950-1 and IEC 60065, has been committed to HBSE for a similar period.

HBSE looks at hazards as energy sources capable of causing pain or injury to an operator. It calls for product designers to identify energy sources, quantify the energy produced, and classify according to the severity of the hazard. By identifying how the energy can be transferred to a body part of the user, it then requires designers to determine appropriate safeguards for people and property and to measure the effectiveness of the safeguards.

IEC 62368-1 defines several types of safeguards, including equipment safeguards such as insulation or protective earthing, installation safeguards, instructional safeguards, precautionary safeguards and skill safeguards that rely on the knowledge and experience of skilled operators.

To support this approach, energy-transfer mechanisms and safeguards are each assessed according to a three-block model.

In keeping with HBSE principles, IEC 62368-1 contains clauses that refer specifically to various forms of energy, including electrical, thermal, chemical, kinetic and radiated energy such as optical, acoustic or others. Many items of ICT/AV equipment will contain more than one of these types of energy sources.

For electrical sources, the energy contained depends on both the voltage and the current. Moreover, the limits specified for class 1, 2 and 3 also depend on the frequency. Up to 1 kHz, the ES1 limit is 30 Vrms, 42.4 Vp and 60 Vdc.
The ES2 limit is 50 Vrms, 70.7 Vp and 120 Vdc.

In a similar way to the outgoing 60950-1 and 60065 standards, 62368-1 defines several categories of users, namely: ordinary person, skilled person, and instructed person.

An ordinary person should not be exposed to energy sources capable of causing injury. At least one safeguard must be provided against class 2 energy sources, and a double or reinforced safeguard for class 3 sources.

A skilled person is expected to be capable of protecting themselves against class 2 and class 3 energy sources, although some safeguards may be required. An instructed person is directly aided by a skilled person and may access energy sources in higher classes than are permitted for an ordinary person but cannot be exposed to energy levels capable of causing injury.

As the least hazardous category, class 1 energy sources require no equipment safeguards to prevent access by any category of user.

The published 62368-1 standard describes the rules on electrically caused injury in Clause 5 of the document. Subsequent clauses cover electrical fire, thermal burn injury and radiation.

Making the transition

The fact that UL/CSA and Cenelec have coordinated their changeovers helps OEMs manage the transition efficiently and ensure their products remain marketable on both sides of the Atlantic after the old standards are withdrawn.

As far as the EU is concerned, Dec. 20, 2020 represents the Date of Withdrawal of 60950-1 and 60065 and is also (following a June 18, 2018 announcement by the EU that harmonized the two deadlines) the date for cessation of presumptions of conformity with other standards that reference the outgoing standards – such as the Low-Voltage Directive (LVD). From this time, the European version, EN 62368-1, will be the only acceptable standard for the categories of products covered.

In North America, the UL/CSA joint body refers to Dec. 20, 2020 as the Effective Date, from which UL 62368-1 will supersede UL 60950-1 and UL 60065 and they will be withdrawn. Although new submissions will be tested according to 62368-1, legacy products that comply with the outgoing standards will not be subjected to an Industry File Review.

Currently, 62368-1, 60950-1 and 60065 are effective, both in the EU and North America. While this eases the transition, OEMs can and should engage with 62368-1 as soon as possible and begin testing their products in accordance with the new standard.

As with 60950-1 and 60065, 62368-1 applies to certain components and subsystems within the product as well as to the end-product itself. This includes built-in power supplies, or external power adapters that ship in the box with the product. To help OEMs manage their existing 60950-1 and 60065 certified parts inventories, the latest edition of 62368-1, Edition 2, contains the following clause, known as clause 4.1.1:

Components & subassemblies that comply with IEC 60950-1 or IEC 60065 are acceptable as part of equipment covered by this standard without further evaluation other than to give consideration to the appropriate use of the component or subassembly in the end-product.

TC108 has also amended 60950-1 and 60065 to permit newer 62368-1 certified parts to be used in products compliant with the outgoing standards. While these allowances ease the transition, it must be noted that clause 4.1.1 is temporary. It will be withdrawn in the EU on Dec. 20, 2020. UL/CSA is awaiting a decision by TC108 on whether to extend the clause into Edition 3 of 62368-1, which is expected to be published sometime in 2019.

To be sure of having the necessary approvals in place ready for the December 2020 deadline, the time to act is now. As the deadline approaches, test houses are likely to be under pressure and lead times could be long.

Studying the standard is essential. Clause 0 of the currently published version offers an overview of the standard and its history, objectives and approaches.

Other useful references include the document IEC/TR 62368-2, Ed. 2, “Audio/video, information and communication technology equipment – Part 2: Explanatory information related to IEC 62368-1”. Available from the IEC store and elsewhere, this provides extra background and explanations of sub-clauses.

In addition, the UL organization has published a transition toolkit, which contains the UL standard document, white papers and brochures, and access to training resources including webinars and regional IEC 62368-1 workshops.

Companies that have not already begun their 62368-1 journey may find that a good place to begin is the CUI white paper on “IEC 62368-1: An Introduction to the New Safety Standard for ICT and AV Equipment,” for more background information on the changes.

References

UL Toolkit for IEC 62368-1, www.62368-ul-solutions.com/toolkit.html

White paper, An Introduction to the new safety standard for ICT and AV equipment,
www.cui.com/catalog/resource/iec-62368-1-an-introduction-to-the-new-safety-standard-for-ict-and-av-equipment.pdf