IEC 62368-1: standard approach - TUV SUD Customer Day 2015 Safety of electronic equipment Philosophy applied: To define hazard-based requirements using engineering principles and taking

IEC 62368-1: A new ‘hazard-based’ standard approach Matthew Emery TÜV SÜD Product Service

Customer Day 2015 15-07-15 TÜV SÜD

Name Matthew Emery

Title: Product Safety Specialist

Employer: TÜV SÜD Product Service

Experience: 8 years experience in Product Testing

History: Worked for lighting manufacturer for 8 years

Telephone: +44 (0)1489 558 128

E-mail: [email protected]

Who am I?

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1 Existing Product Safety Standards

2 Introduction to IEC 62368-1

3 Injury Classification

4 Energy Sources

5 Safeguards

Introduction

6 Models for Protection

15-07-15 Customer Day 2015

Customer Day 2015 15-07-15

Existing product safety standards: • Blurred borderline between different classes of products • Too diverse: safety requirements differed widely due to the evolution of

“Multi-Media” products • Changed too frequently because: − design oriented rather than performance based − Maintenance cycles required for any technology evolution

• Were lacking for some product families

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ECMA - 287


Safety of electronic equipment Philosophy applied: To define hazard-based requirements using engineering principles and taking into account relevant IEC standards and pilot documents. Where technical discrepancies between standards emerged, conclusion was based on engineering principles.

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Standard ECMA-287:1999


• Technology independent safety standard • Scope is ICT and CE equipement rated less than 600Vrms • Covers products currently under the scope of IEC 60065 and IEC 60950-

x • New standard NOT simply a merger of IEC 60065 and IEC 60950) • ECMA International Technical Committee 12 draft, based on IEC basic

safety publications and HBSE (Hazard Based Safety Engineering) principles

• Free to download - http://www.ecma-international.org/publications/standards/Ecma-287.htm

• Contributed to IEC TC108 for further elaboration

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ECMA-287 - Facts

http://www.ecma-international.org/publications/standards/Ecma-287.htm�


• New safety standard (NOT a merger of IEC 60065 and 60950-1) • Covers products currently under the scopes of IEC 60065 and IEC

60950-x • Hazard based • Technology independent • Based on sound engineering principles, research and field data

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IEC 62368-1 – What is it?


• Clearly identify the hazard being addressed • Clearly state principles upon which hazard is addressed • Follows of IEC pilot publication • Use of IEV definitions • Performance based (conformance based on tests rather than on

construction) • Type test standard • Useful to designers • Suitable to assess conformance by suppliers, purchasers and certifiers

(but NOT a certification document) • Meet above in a “user friendly” manner

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IEC 62368-1 – Objectives


The standard: • Covers all specified hazards • Each hazard will be in a separate section • Will include examples of accepted constructions • Include basics of three block model in “Principles of Safety” • Adjunct Documents − Interpretations

(clarification of standard, newly identified accepted constructions, etc.) − Part 2 documents for a few very special cases

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IEC 62368-1 – Structure


For each hazard clause will be formatted as follows: • Clause − State objective of clause

• Specify the energy source (as far as possible three (3) levels) and define the limits between the energy levels − Specify principal; supplemental and reinforced safeguards

• Location of safeguard − Specify safeguard properties − Specify safeguard parameters (e.g. materials)

• Specify safeguard tests/construction

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IEC 62368-1 – Format


HAZARD, HAZARDOUS: An energy source that exceeds body susceptibility limits. ISO/IEC Guide 51: potential source of harm SAFE, SAFETY: Situation where at least one safeguard is interposed between the body and a hazardous energy source. ISO/IEC Guide 51: freedom from unacceptable risk

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IEC 62368-1 – Definitions


Injury occurs ONLY when energy of sufficient magnitude and duration is imparted to a body part.

Body Transfer mechanism

Hazardous energy source

(capable of causing pain or inquiry)

Energy source Effect on the body Effect on combustible materials

Class 1 Not painful, but may be detectable Ignition not likely

Class 2 Painful, but not an injury Ignition possible, but limited growth and spread of fire

Class 3 Injury Ignition likely, rapid growth and spread of fire

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IEC 62368-1 – Injury Classification


• Electric shock energy source • Electrically caused fire energy source • Chemical energy source (e.g. chemicals (including batteries)) • Mechanical energy source (e.g. moving parts, sharp edges, physical

stability) • Thermal energy source (e.g. skin burn) • Radiation energy source (e.g. ionizing, non-ionizing, acoustic)

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IEC 62368-1 – Energy Sources


Forms of energy Examples of body response or property damage Clause

Electrical energy = ES (e.g. energized conductive parts)

Pain, fibrillation, cardiac arrest, respiratory arrest, skin burn, internal organ burn 5

Thermal energy = PS (e.g. electrical ignition, spread of fire)

Electrically caused fire leading to burn related pain or injury or property damage 6

Chemical reaction (e.g. electrolyte, poison) Skin damage, organ damage, or poisoning 7

Kinetic energy = MS (e.g. moving parts of equipment, or a moving body part against an equipment part)

Laceration, puncture, abrasion, contusion, crush, amputation, or loss of a limb, eye, ear

8

Thermal energy = TS (for example, hot accessible parts)

Skin burn 9

Radiated energy = RS (e.g. electromagnetic, optical, acoustic)

Loss of sight, skin burn, or loss of hearing 10

Examples of body response or property damage related to energy sources

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IEC 62368-1 – Body Response/Property Damage


Unless otherwise specified, a class 1 source is an energy source with levels not exceeding class 1 limits under: • normal operating conditions; and • abnormal operating conditions that do not lead to a single fault condition;

and • single fault conditions that do not result in class 2 limits being exceeded. Under normal operating conditions and abnormal operating conditions, the energy in a class 1 source, in contact with a body part, may be detectable, but is not painful nor is it likely to cause an injury. For fire, the energy in a class 1 source is not likely to cause ignition. Under single fault conditions, a class 1 energy source, under contact with a body part, may be painful, but is not likely to cause injury. TÜV SÜD

IEC 62368-1 – Class 1 Energy Source


Class 2 energy source Unless otherwise specified, a class 2 source is an energy source with levels exceeding class 1 limits and not exceeding class 2 limits under normal operating conditions, abnormal operating conditions, or single fault conditions. The energy in a class 2 source, under contact with a body part, may be painful, but is not likely to cause an injury. For fire, the energy in a class 2 source can cause ignition under some conditions. Class 3 energy source A class 3 source is an energy source with levels exceeding class 2 limits under normal operating conditions, abnormal operating conditions, or single fault conditions, or any energy source declared to be a class 3 source. The energy in a class 3 source, under contact with a body part, is capable of causing injury. For fire, the energy in a class 3 source may cause ignition and the spread of flame where fuel is available.

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IEC 62368-1 – Classes 2 & 3 Energy Source


A safeguard is a device or scheme or system that: • Is interposed between an energy source capable of causing pain or injury

and a body part, and • Reduces the likelihood of transfer of energy to a body part

Body Safeguard Hazardous energy sources

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IEC 62368-1 – Safeguards


Injury does not occur when the energy source is non-hazardous.

Body No safeguard necessary

Non-hazardous energy source

A non-hazardous energy source is: An energy source that is less than the body susceptibility to that energy

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IEC 62368-1 – Non-hazardous Energy Source


A BASIC SAFEGUARD is: A safeguard that is effective under normal and abnormal operating conditions whenever hazardous energy is present

Body Basic safeguard


Supplementary safeguard

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A SUPPLEMENTARY SAFEGUARD is: A safeguard that is effective in the event of a single fault of any part, including a fault of the basic safeguard

IEC 62368-1 – Supplementary Safeguards


A REINFORCED SAFEGUARD is: A single, robust safeguard that is effective under normal operating conditions, abnormal operating conditions, and single fault condition.

Body Reinforced safeguard


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IEC 62368-1 – Reinforced Safeguard


Hierarchy of safeguards I. Equipment safeguards are always useful, since they do

not require any knowledge or actions by persons coming into contact with the equipment

II. Installation safeguards are useful when a safety

characteristic can only be provided after installation (e.g. equipment has to be bolted to the floor to provide stability)

III. Behavioural safeguards are useful when the equipment requires an energy source to be accessible.

Safeguard

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IEC 62368-1 – Hierarchy of Safeguards


Basic safeguard


Reinforced safeguard

Effective under normal operating conditions

Effective in the event of failure of the basic safeguard

Effective under normal operating conditions and in the event of a single fault condition

Example: Basic Insulation

Example: Supplementary Insulation

Example: Reinforced Insulation

Example: Normal temperatures below ignition temperatures

Example: fire enclosure Not applicable

Equipment safeguard: Physical part of an equipment

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IEC 62368-1 – Equipment Safeguard


Basic safeguard



Effective under normal operating conditions

Effective in the event of failure of an equipment basic safeguard

Effective under normal operating conditions and in the event of a single fault condition elsewhere in the equipment

Example: Wire size

Example: Overcurrent protective device

Example: Socket outlet

Installation safeguard: Physical part of a man-made installation

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IEC 62368-1 – Installation Safeguard


Basic safeguard



In the absence of any equipment safeguard, effective under normal operating conditions


In the absence of any equipment safeguard, effective under normal operating conditions and in the event of a single fault con-dition elsewhere in the equip-ment

Example: Gloves

Example: Insulating floor mat

Example: Electrically-insulated glove for handling live conductors

Personal safeguard: Physical device worn on the body

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IEC 62368-1 – Personal Safeguard


Basic safeguard



In the absence of any equipment safeguard, effective under normal operating conditions


Only effective on an exceptional basis, when providing all appropriate safeguards would prevent the intended functioning of the equipment

Example: Instructional safeguard to disconnect telecommunication cable before opening cover

Example: After opening a door, an instructional safeguard warning against hot parts

Example: Instructional safeguard warning of hot parts in a photocopier, or a continuous roll paper cutter on a commercial printer

Instructional safeguard: Voluntary or instructed behaviour

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IEC 62368-1 – Instructional Safeguard


Accessibility to electrical energy sources and safeguard

Q: What are the requirements between these non-accessible sources? A: None, as the enclosure is double insulated, the sources are not accessible.

Equipment Enclosure Double Insulated

ES 3 source

ES2 source

ES1 source

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IEC 62368-1 – Accessibility to Energy Sources


Accessibility to electrical energy sources and safeguard Now there is an accessbile connection

A: 1. Basic insulation between ES1 & ES2 A: 2. Double or reinforced insulation between ES1 & ES3 A: 3. Insulation between ES2 & ES3 depends on the insulation between ES1 & ES2

Accessible Part/Interface


ES 3 source

ES2 source

ES1 source

?

Q: What are the requirements between the sources in this case?

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Accessibility to electrical energy sources and safeguard Now there are two accessible connections from independent sources

Accessible Connection


ES1 source

ES1 source

Q: What are the requirements between the sources in this case?

A: 1. According to B.4 (single fault condition), the insulation or any components between the sources need to be shorted A: 2. If one of the two ES1 sources would reach ES2 levels - basic safeguard (Note that a source that exceeds ES1 levels is not an ES1, but an ES2 source!!!) A: 3. If both ES1 sources stay within ES1 limits - no safeguard (functional insulation)

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Ordinary person: all persons other than “instructed” and “skilled”. Includes users and persons who may have access to or be in the vicinity of the equipment. Under normal or abnormal operating conditions, should not be exposed to energy sources capable of causing pain or injury. Under a single fault condition should not be exposed to energy sources capable of causing injury. Instructed person: instructed and trained or supervised by a skilled person to identify energy sources that may cause pain and to take precautions to avoid unintentional contact or exposure. Under normal operating conditions, abnormal operating conditions or single fault conditions, should not be exposed to energy sources capable of causing injury. Skilled person: persons who have training or experience in the equipment technology, particularly knowing the various energies and magnitudes used. Expected to use their training and experience to recognize energy sources capable of causing pain or injury and to take action for protection. Should be protected against unintentional contact or exposure to sources capable of causing injury.

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IEC 62368-1 – Behavioural Safeguards


Person Behavioural safeguards Ordinary Instructional safeguard: means of providing information, describing the existence and location of an

energy source capable of causing pain or injury Intended to invoke a specific behaviour to reduce the likelihood of transfer of energy to a body part.

Instructional safeguards may be considered acceptable protection to bypass an equipment safeguard such that the person is made aware of how to avoid contact with a class 2 or class 3 energy source.

Instructed Precautionary safeguard is the training and experience or supervision of an instructed person by a skilled person to use precautions to protect the person against class 2 energy sources. During equipment servicing, an instructed person may need to remove or defeat an equipment safeguard. In this case, an instructed person is expected to then apply precaution as a safeguard to avoid injury.

Skilled Skill safeguard is the education, training, knowledge and experience of the skilled person that is used to protect that person against class 2 or class 3 energy sources. During equipment servicing, a skilled person may need to remove or defeat an equipment safeguard. In this case, a skilled person is expected to then apply skill as a safeguard to avoid injury

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IEC 62368-1 – Behavioural Safeguards


The limit values for determining whether or not an energy source is hazardous and the safeguard tests and parameters are based on IEC Basic and Group safety publications.

No

No

IDENTIFY ENERGYSOURCE

IS SOURCEHAZARDOUS?

IDENTIFY MEANS BY WHICHENERGY CAN BE

TRANSFERRED TO A BODY PART

DESIGN SAFEGUARD WHICHWILL PREVENT ENERGY

TRANSFER TO A BODY PART

MEASURE SAFEGUARDEFFECTIVENESS

IS SAFEGUARDEFFECTIVE?

DONE

Yes

Yes

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IEC 62368-1 – Limit Values


1. Identify the ES1, ES2 and ES3 parts and circuits and their respective safeguards (ES = Electrical energy)

2. Identify the PS1, PS2, and PS3 circuits and the fire safeguard methods (PS = Thermal energy)

3. Identify the MS1, MS2, and MS3 parts and circuits and their respective safeguards (MS = Kinetic energy)

4. Identify the TS1, TS2, and TS3 parts and circuits and their respective safeguards (TS = Thermal energy)

5. Identify the RS1, RS2, and RS3 parts and circuits and their respective safeguards (RS = Radiated energy)

No

No

IDENTIFY ENERGYSOURCE

IS SOURCEHAZARDOUS?

IDENTIFY MEANS BY WHICHENERGY CAN BE

TRANSFERRED TO A BODY PART

DESIGN SAFEGUARD WHICHWILL PREVENT ENERGY

TRANSFER TO A BODY PART

MEASURE SAFEGUARDEFFECTIVENESS

IS SAFEGUARDEFFECTIVE?

DONE

Yes

Yes

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IEC 62368-1 – Limit Values


IEC 62368-1 – Electric Shock


General Information Energy Source Result

Dia-gram Ref-erence

Operating Reference

Area of Contact

Frequency, Capacitance

or Pulse Duration

Determined Voltage Applicable

Voltage Limit

Determined Current

Appli-cable

Current Limit

Classification

L M S V Peak

V RMS Peak/RMS mA Peak

mA RMS

Peak/RMS

ES1 ES2 ES3

C1 Normal X 50-60Hz - 240 - - - - X C2 Normal X DC - 25.2 28Vdc - - - X C2 Faut F10 X DC - 28.6 40Vdc - - - X C1-C2 Normal - - - 100kHz 580 456 - - - - X C3 Normal X DC - 5.2 28Vdc - - - X C3 Fault F11 X DC - 5.4 40Vdc - - - X C3 Fault F12 X Hiccup 8.6 - 40Vdc - - - X C2-C3 Normal X 30kHz 69 45 65Vrms - - - X C4 Normal X DC - 3.4 28Vdc - - - X C4 Fault F13 X DC - 3.5 40Vdc - - - X C5 Normal X 60kHz/0.8nF 2500 - 5000Vpeak - 27 30 X C5 Fault F14 X 30kHz/0.8nF 1000 - 5000Vpeak - 33 35 X C6 Normal X 1kHz 35 - 42.4Vpeak - - - X C6 Fault F15 X DC - 24 40Vrms - - - X C7 Normal X Non-DC 120 140Vrms - - - X

Electrical energy source classification table

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IEC 62368-1 – Energy Source Classification


Clause OVERVIEW OF EMPLOYED SAFEGUARDS 5.2 Electrically-caused injury

Body Part (e.g. Ordinary)

Energy Source (ES3: Primary Filter circuit)

Related clause (e.g., 5.3.6.3, etc.)

Safeguards

Basic Supplementary Reinforced (Enclosure)

6.2.2 Electrically-caused fire

Material part (e.g. mouse enclosure)

Energy Source (PS2: 100 Watt circuit)

Related clause (6.4.3.1)

Safeguards

Basic Supplementary (e.g., PTC)

Reinforced

7.5 Chemically-caused injury

Body Part (e.g., skilled)

Energy Source (e.g., hazardous material)

Related clause (7.4)

Safeguards

Basic (e.g. gloves)

Supplementary Reinforced

8.2 Mechanically-caused injury

Body Part (e.g. Ordinary)

Energy Source (MS3:Imploding part)


Safeguards

Basic Supplementary Reinforced (Enclosure)

9.3 Thermal Burn

Body Part (e.g., Ordinary)

Energy Source (TS2)


Safeguards

Basic (e.g. Instructional)


10.2 Radiation

Body Part (e.g., Ordinary)

Energy Source (Output from audio port)

Related clause (10.4.2)

Safeguards

Basic (e.g., Instructional)


Supplementary Information: (1) A block diagram can be attached to further detail the identified safeguards.

(2) “N” – Normal Condition; “A” – Abnormal Condition; “S” Short Circuit

TEST REPORT IEC 62368-1 Audio/video, information and communication technology equipment Part 1: Safety requirements

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IEC 62368-1 – Example Test Report


Electrical energy transfer occurs when there are two or more electrical contacts to the body: The first electrical contact is between a body part and a conductive part of the equipment; the second electrical contact is between another body part; and earth, or another conductive part of the equipment.

Energy transfer

mechansm

Energy source Body

Prospective touch voltage or

touch current

Two electrical contacts Body resistance

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IEC 62368-1 – Electrical Energy Transfer


Models for protection against electrically-caused pain or injury Protection against electrically-caused pain or injury requires that one or more safeguards be interposed between an electrical energy source capable of causing pain or injury and a body part.

Safeguard Energy source Body

Prospective touch voltage and

touch current Electric insulation Body resistance

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IEC 62368-1 – Models for Protection


Models for electrically-caused fire Electrically caused fire is due to conversion of electrical energy to thermal energy, where the thermal energy heats a fuel material followed by ignition and combustion.

Energy transfer mechansm Energy source Fuel material

Electrical energy conversion to thermal

energy

Conduction, convection,

radiation

Material exceeds ignition temperature

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IEC 62368-1– Models


Models for protection against electrically caused fire The basic safeguard against electrically caused fire is that the temperature of a material, under normal operating conditions and abnormal operating conditions, does not cause the material to ignite. The supplementary safeguard against electrically-caused fire reduces the likelihood of ignition or, in the case of ignition, reduces the likelihood of spread of fire.

Safeguard Energy source Fuel material


energy Thermal resistance

Material does not exceeds ignition

temperature Fuel material Energy source Safeguard


energy Fuel ignition Enclosure contains

the fire

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IEC 62368-1– Models for Protection


SAFEGUARDS against electrically caused fire

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IEC 62368-1– Safeguards


IEC 62368-1–Models for Chemical Injury


IEC 62368-1–Models for Chemical Injury


MS = Kinetic energy MS1 - Mechanical energy source with levels not exceeding MS1 limits under normal operating conditions and abnormal operating conditions and not exceeding MS2 under single fault conditions. MS2 - Mechanical energy source with levels not exceeding MS2 limits under normal operating conditions, abnormal operating conditions, and single fault conditions, but is not MS1. MS3 - Mechanical energy source with levels exceeding MS2 limits under normal operating conditions, abnormal operating conditions or single fault conditions, or any mechanical energy source declared to be treated as MS3 by the manufacturer.

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IEC 62368-1– Definitions


Models for thermally-caused injury Thermally caused injury may occur when thermal energy capable of causing injury is transferred to a body part .

Energy source Body part

Energy transfer

mechansm Energy source Body

Temperature, Material, Mass, etc.

Body part touches hot part

Body part thermal resistance

Safeguard Energy source Body

Temperature, Material, Mass, etc.

Thermal insulation Body part thermal resistance

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IEC 62368-1– Models for Thermally-Caused Fire


TS = Thermal energy TS1 - Thermal energy source with temperature levels not exceeding TS1 limits under normal operating conditions; and not exceeding TS2 limits under abnormal operating conditions; or single fault conditions. TS2 - Thermal energy source where the temperature exceeds the TS1 limits; and under normal operating conditions, abnormal operating conditions or single fault conditions the temperature does not exceed the TS2 limits. Where the malfunction of the equipment is evident, no limits apply. TS3 - Thermal energy source where the temperature exceeds the TS2 limits in Table 38 under normal operating conditions or under abnormal operating conditions, or under single fault conditions.

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IEC 62368-1– Definitions

TÜV SÜD Product Service Slide 46 Customer Day 2015 15-07-15

Thank you for listening Matthew Emery Product Safety Specialist TÜV SÜD Product Service +44 (0)1489 558128 [email protected]