he UL/EN/IEC 62368 standard is a merger of two standards—UL/EN/IEC 60065 Audio and Video Equipment and UL/EN/IEC 60950 Information and Communication Equipment. As with other standards, there are different versions or editions of the standard such as IEC 62368-1 2014. As this standard applies to a broad range of popular applications, many designers are affected by its requirements.

Most designers probably have some familiarity with 62368 because the industry has been transitioning to this standard for several years, and, within the U.S., this standard replaced the legacy standards in June 2019 for any new products seeking certification. However, there's another regulatory milestone looming as the legacy standards in the European Union are about to be withdrawn on December 20, 2020, making this essentially the adoption date for 62368 in the EU. (1)

As this deadline approaches, many designers may still need to come up to speed on what the standard requires, and understand what variations of the standard are being applied as well as aspects of the standard that are still in flux. With that in mind, we present a brief overview and update on UL/EN/IEC 62368, noting the status of various versions of the standard in different countries and sources for further information. We also highlight a few elements of IEC 62368 such as standards-related terminology, touch temperature limits and two application areas that will be impacted by anticipated changes in IEC 62368, namely indoor and outdoor equipment and products with USB and PoE interfaces.

Label Reform

Under the emerging regulatory changes, the label on each of the appliance products changes and there are new requirements for each product. For example, the labeling required in the old (EC) no 642/2009 and (EU) 1062/2010, which apply to TVs and monitors, changes in the new regulation. While the existing product ratings assign A, A+, A++, and A+++, the new rating system goes from A through G (more on this in the section on Displays).

Safety and Hazard Based

IEC 62368 is not a rule-based standard but rather a safety and hazard-based standard. Audio and video equipment and information communications equipment have many ports such as USB and the newer USB Type C ports. The computer monitor has ports that the consumer or user can touch. The manufacturers are now requested to present hazards to the safety agencies including voltage, and temperatures of the various surfaces. 

Table 1. IEC 62368 implementation by country or region. [2]

It has taken time for the various agencies to create a harmonized standard. Each region of the world has its own version and implementation date as seen in Table 1.

UL has given a number of presentations and overviews concerning the standard. One of the earlier presentations was an IEC 62368-1 overview given by Thomas Burke a principal product safety engineer, Consumer and Enterprise Tech Equipment at UL, on June 7, 2017 to PSMA. A recording of the presentation along with the slides is available on the Safety and Compliance Forum on the PSMA website.

More recently Dennis Butcher, senior project engineer, Ctech EULA, gave a webinar presentation on July 28, 2020 "The Adoption of IEC 62368-1 3rd Edition and IEC 62368-3."[3] This presentation is available from UL's Toolkit page. This web page offers resources to help engineers and compliance engineers navigate the IEC 62368-1 3rd Edition from UL 60065 and the UL 60950 standards. 
There are a number of editions to IEC 62368-1 including 62368-1 2nd Edition 2014, which is often cited in the literature. There's also UL/CSA 62368-1 3rd Edition. which was published Oct. 4, 2018. This paper cannot address many of the differences found in the variations because these variations apply to different products and each product is different and has different uses. 

Testing and Design Assistance

Many companies have a compliance engineering department. This department gathers the standards for the products for safety and regulations for various parts of the world where the company's products are sold. The compliance department needs to have a good understanding of the language used in the standards because in many cases, this language may not be understood by design engineers. The following was taken from the Thomas Burke presentation defining some differences. 

Table 2. Definitions used by IEC 60950-1 verse IEC 62368-1. [2]

Hazards

In products where consumers can touch various parts of the product, there are issues with both temperature and electric shock. Table 3 lists temperature limits under the standard for accessible (touchable) parts.

Table 3. Touch temperature limits imposed by IEC 62368-1. [2]

Indoor Outdoor Equipment

Because the 62368 standard did not address all industry concerns, there are cases where it has not supplanted the old standard. This is true for outdoor applications. As the following excerpt [3] explains, the second edition of 62368 still references IEC 60950-22 with regard to outdoor equipment. However, the third edition of the standard will include the 60950-22 requirements in an Annex Y as noted. Some of these requirements are still not fully defined. So, some unsettled issues remain and other agencies will need to help address what is to be applied.  

USB And PoE

Another case where the legacy 60950 requirements have remained in effect are the interfaces that transmit both data and power. For example, many pieces of equipment use USB for both data and power. This is true for the newer USB Type C cables that can eliminate product power supplies and the associated ac power cords.

Similarly, many security cameras and monitors use CAT 5 and CAT 6 cables for both power and data information following the power over Ethernet (PoE) standards. Both of these interfaces will be covered in the third edition of IEC 62368-1 as shown in the following excerpt. [2]
There are newer lighting products that are using CAT 5 and CAT 6 cable systems for both hallway lighting in hotels and security cameras. Some of these systems have backup dc power in case of a power outage. These systems use the new LED lights, allowing lower power consumption and long periods of operation such as two or three hours, which was unheard of with emergency exit lighting and security cameras in the past.
These lighting products came onto the market after the 62368 was initially published so they weren't covered. And there are others such as video doorbells, which can use the existing power and can even have a battery backup using Li-ion batteries. But it's expected that these products will be covered in the third or fourth editions.

References

1. "Getting to Know IEC 62368-1—How Does A TV/Stereo Standard Affect My Industrial Power Electronics Design?" by Kevin Parmenter and James Spangler, How2Power Today, November 2017
2. "IEC 62368-1 Overview" by Tom Burke, UL Presentation to PSMA Safety & Compliance Committee, 6/7/2017.
3. "The Adoption of IEC 62368-1 3rd Edition and IEC 62368-3"webinar by Dennis Butcher, July 2020, available at "UL's ToolKit for Your 62368-1 Transition".

Kevin Parmenter Director of Applications Engineering Taiwan Semiconductor America

Jim Spangler President Spangler Prototype Inc. (SPI)

Editor's Note: This article was first published in the September 2020 issue of How2Power Today (http://www.how2power.com/newsletters/index.php).

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