FEATURE ELECTRICAL & ELECTRONIC COMPONENTS


energy levels (Class 1, 2, or 3) and identify if the sources are hazardous.


• If they are hazardous, identify the means by which energy can be transferred to a body part and design the safeguards that will stop this and measure their effectiveness. There is a hierarchy of safeguards,


IEC 62368-1:2018: Setting new standards


As innovation has seen the lines blur between previously distinct technologies, compliance requirements for multi-media products were increasingly falling in both IEC 60065 (AV equipment) and IEC 60950-1 (IT equipment). A new standard,


IEC 62368-1:2018 (Audio/video, information and communication technology equipment - Part 1: Safety requirements), will


therefore supersede them both from 20 December 2020, as Richard Poate, Senior Manager at TÜV SÜD, explains


I


EC 62368 is not simply a merger of the two old standards – whilst it still


contains some of the same specific compliance criteria as its predecessors, it has a different structure. It also follows a completely different methodology as it is the first time that a hazard-based approach has been taken for these types of products. However, the new hazard- based philosophy of IEC 62368 makes it a technology-independent safety standard that should offer more future- proofing and introduce greater design freedoms, leading to the creation of safer products for end users. The previous two standards closely dictated product design and were known


sources and the mechanisms by which they may transfer energy to a user. This means that manufacturers must no longer prove that prescribed requirements have been met, but it requires them instead to demonstrate that hazards have been identified and considered, that appropriate safeguards have been implemented, and that the performance of those safeguards has been suitably tested and evaluated. There must also be evidence that the product has been designed to be safe to use in the expected context. While IEC 60065 and IEC 60950-1


followed a set of specific rules and criteria outlined in both standards,


“While IEC 60065 and IEC 60950-1 followed a set of specific rules and criteria outlined in both standards, IEC 62368-1 requires the


identification of safety hazards in the early product development phase, so that subsequent product design eliminates them”


as ‘prescriptive’ standards. Rather than prescriptive tests, IEC 62368 uses a performance methodology to assess the safeguards incorporated to protect against the potential risks presented by identified hazards. Hazard-based Safety


Richard Poate 16


Engineering (HBSE) principles are intended to protect end-users by identifying any potentially hazardous energy


JULY/AUGUST 2020 | DESIGN SOLUTIONS


IEC 62368-1 requires the identification of safety hazards in the early product development phase, so that subsequent product design eliminates them. It also provides more performance options to demonstrate compliance. The following is a typical example of


the Hazard Based Approach: • Identify the energy sources by reviewing the product and its associated schematics.


• Take measurements to determine the


which can be applied, that must be taken into account: 1. Equipment safeguards - do not require any knowledge or actions by persons coming into contact with the equipment.


2. Installation safeguards - when a safety characteristic can only be provided after installation. For example, the equipment has to be bolted to the floor to provide stability.


3. Behavioural safeguards - when the equipment requires an energy source to be accessible.


A NEW APPROACH IEC 62368-1 introduces a completely new methodology, taking the well-established and understood principles of IEC 60065 and IEC 60950-1 and turning them on their heads. This means that a new mind- set is needed when applying the standard. Product designers must also recognise that the new standard applies not only to the end product but to major components and subsystems, such as power supplies. The prescriptive test-based approach


of the old standards left little room for subjectivity, as they require engineers to apply specific tests to prove compliance. The introduction of IEC 62368 sees us move from an objective method of proving compliance to a more subjective approach, which relies on engineering expertise to identify potential hazards. However, ‘to err is human’ and it’s critical that care is taken to identify all the potential hazards and transfer mechanisms and to make sure the employed safeguards are appropriate. The advantage for any manufacturers


that were early adopters during the standard’s transition period, is that they have had plenty of time to become familiar with the new standard and adapt their design approaches accordingly. With the transition period coming to an end in less than five months, it is therefore vital that the fundamental concepts and the differences of this ‘hazard based’ standard approach are fully understood. However, jumping straight into full testing can be expensive and risky if you are not sure if the product will comply. Our advice would be to conduct a pre-


compliance review which will highlight any areas of non-compliance and what delta testing may be necessary to make the product compliant to the new standard.


TÜV SÜD www.tuv-sud.co.uk / DESIGNSOLUTIONS


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