IEC 60621-2:1987

FOREWORD
PREFACE
CHAPTER I: PROTECTION AGAINST DIRECT CONTACT
Clause
Introduction
1 General requirements
2 Complete protection by means of barriers or enclosures
3 Complete protection by insulation of live parts
4 Partial protection by placing live parts out of reach
5 Partial protection by the provision of obstacles
6 Minimum distances to be observed in operating and
   maintenance gangways for indoor installations
7 Minimum clearances for outdoor installations
CHAPTER II: PROTECTION AGAINST INDIRECT CONTACT - A.C.
Introduction
8 General
9 TN, TT and IT systems description
10 Protective measures for TN systems
11 Protective measures for TT systems
12 Protective measures for IT systems
13 Requirements for earth fault current limitation devices
14 Earthing arrangements and protective conductors
CHAPTER III: PROTECTION AGAINST OVERCURRENT AND
FAULT CURRENT
Introduction
15 General rule
16 Nature of protective devices
17 Automatic interruption - Protection against overcurrent
   due to overload
18 Automatic interruption - Protection against short circuits
19 Co-ordination of overload and short-circuit protection
20 Limitation of overcurrent by characteristics of supply
   or load
CHAPTER IV: THE SELECTION OF PROTECTIVE DEVICES AND
            PROTECTION SYSTEMS
Introduction
21 Basic requirements
22 Selection procedure
23 Discrimination between protective devices
APPENDIX A - Selection of factor k for calculating the
             minimum cross-sectional area of protective
             conductors
APPENDIX B - Description of certain types of protective
             devices and their uses

Applies to all installations with voltages up to and including 1 000 V as well as with those above 1 000 V. Describes protective measures intended to ensure the safety of persons from electric shock in normal service and in case of fault. Also, particular requirements applicable to TN, TT and IT system earthing. Extends the principles to the protection against overcurrent in respect of overload and short-circuit protection, together with the co-ordination of overload and short-circuit protection and the coordination of this protection with the conductors and apparatus. Also, the principles developed in IEC 60364 for the protection of conductors are extended to the protection of apparatus in respect of security of the installation and protection of personnel.