by SGS Group
On December 20, 2020, the mandatory safety standard for audio, visual, information and communication equipment, under the requirements of the European Union’s (EU) Low Voltage Directive (LDV) and Radio Equipment Directive (RED), will become EN 62368-1.
EN 62368-1, and the US version UL 62368-1, are based on IEC 62368-1(edition 2.0). This replaces IEC 60950-1 and IEC 60065, both of which will become obsolete. However, IEC 62368-1 differs greatly from those standards, having been completely rewritten using a different structure and logic.
IEC 62368-1 has three editions, 1.0, 2.0 and 3.0, which are built around the following core principles:
- Principle 1: Product Safety Realization Steps
- Principle 2: Safeguards
- Principle 3: Energy Source classification
Understanding the principles and safeguards enshrined in IEC 62368-1 is the key to remaining compliant after December 2020. Looking at Principles 1 and 2 in relation to editions 2.0 and 3.0 will give stakeholders a good understanding of the changes and how they should navigate them.
Principle 1: Product Safety Realization Steps
The concept behind Principle 1 has been adopted from ISO/IEC Guide 51:2014.
The logic this principle follows can be summed up as:
- Step 1 – use as low energy as possible to operate the product. If this is low enough, the product will inherently be safe to use and no safeguards will be required
- Step 2 – when higher and more hazardous energy levels are required; the product’s design must include sufficient safeguards to protect the user from these hazard(s)
- Step 3 – if equipment safeguards conflict with the product’s intended use, making the safeguards impractical, instructional safeguards must be used
- Step 4 – additional safeguards beyond product design will be required if Steps 2 and 3 prove to be insufficient or not applicable
Using this principle, manufacturers should be able to design safer and more compliant products that comply with the requirements of IEC 62368-1.
Principle 2: Safeguards
This is systematically introduced in IEC 62368-1.
It may initially look quite complicated – Supplementary Safeguards, Instructional Safeguards, Skill Safeguards, etc. – but in fact the concept can quite easily be understood.
Safeguards are divided by two methods – Approaches or Levels. These refer to:
- Approaches – methods by which the safeguard functions
- Levels – the strength of the safeguard
Stakeholders should be aware the safeguards in grey – Installation, Personal, Precautionary, Skill – are not specified in IEC 62368-1. Instead, they are assumed effective when the term is used.
Application of Safeguards
Application of the safeguard requirements in IEC 62368-1 can be understand by looking at the issue from two perspectives:
- Safeguards by different approaches
- Safeguards by different levels
Looking at the application of safeguards via the different approaches method, the safeguards should be applied with reference to the Risk Reduction Measures contained in ISO/IEC Guide 51.
Looking at illustration three, the:
- Left column gives a logical step-by-step approach to reducing risk, as defined in ISO/IEC Guide 51
- Middle column details the logic in IEC 62368-1 for how to protect users using different safeguards (NB Equipment Safeguard is highlighted because it is the primary content of IEC 62368-1)
- Right column gives examples of application with reference to clause 4.8 of IEC 62368-1, consumer remote controllers
Looking at the application of safeguards via the different levels method, requires the manufacturer to categorize the safeguards into two levels:
- Level 1: Basic Safeguard, Supplementary Safeguard
- Level 2: Double Safeguard, Reinforced Safeguard
The manufacturer must then consider safeguard levels with reference to the different types of user and energy source. A simplified version can be seen in illustration four. There are three basic types of user and three types of energy source:
- Users – Skilled Person, Instructed Person and Ordinary Person
- Energy sources – Class 1, Class 2 and Class 3
Vulnerability, and therefore the number of safeguards the product will need, is related to the skill of the user and the danger represented by the energy source. For example, according to illustration four, an ordinary person using a Class 3 product means two levels of safeguard but a skilled person using a Class 1 product used by a skilled person would require no safeguard.
The EU and North America will make the application of IEC 62368-1 and UL 62368-1 mandatory in December 2020. Manufacturers and suppliers of audio, visual, information and communication equipment are advised to now check they understand the principles and safeguards enshrined in IEC 62368-1, in order to ensure their products remain compliant after the effective date.
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