Electrical Safety

Contents
Preface
1 Basic Definitions and Nomenclature 1
1.1 Introduction 1
1.2 Basic Definitions and Nomenclature 1
1.2.1 Basic Insulation 1
1.2.2 Class 0 Equipment 1
1.2.3 Class I Equipment 2
1.2.4 Class II Equipment 2
1.2.5 Class III Equipment 2
1.2.6 Direct Contact 2
1.2.7 Indirect Contact 2
1.2.8 Disconnection of Supply 2
1.2.9 Exposed-Conductive-Part (ECP) 2
1.2.10 Extra-Low Voltage 2
1.2.11 Extraneous-Conductive-Part (EXCP) 3
1.2.12 Functional Insulation 3
1.2.13 Ground 3
1.2.14 IT Grounding System 3
1.2.15 Neutral-Protective Conductor (PEN) 4
1.2.16 Protective Bonding Conductor 4
1.2.17 Protective Conductor (PE) 4
1.2.18 Remote or Zero Potential 4
1.2.19 TN Grounding System 5
1.2.20 TN-C Grounding System 5
1.2.21 TN-C-S Grounding System 5
1.2.22 TN-S Grounding System 5
1.2.23 TT Grounding System 5
1.2.24 Prospective Touch Voltage 6
1.2.25 Touch Voltage 71.2.26 Prospective Step Voltage 7
1.2.27 Step Voltage 7
2 Fundamentals of Electrical Safety 9
2.1 Introduction 9
2.2 Protection Against Direct Contact 10
2.2.1 Insulation of Live Parts 10
2.2.2 Enclosures and Barriers 11