CONTENTS

 1     Scope
 2     References
 3     Definitions and abbreviations
        3.1     Definitions
        3.2     Abbreviations
        3.3     Symbols
 4     Overvoltage and overcurrent conditions
 5     Resistibility requirements (basic and enhanced)
        5.1     Basic resistibility requirement
        5.2     Enhanced resistibility requirement
 6     Equipment boundary
 7     Test conditions
 8     Protection coordination
        8.1     General
        8.2     Lightning
        8.3     Power induction, earth potential rise and power contact
        8.4     Special test protector
                  8.4.1     Switching type protector
                  8.4.2     Clamping type protector
                  8.4.3     Multistage modules
 9     Acceptance criteria
10     Tests
       10.1     Symmetric pair port
                 10.1.1     Lightning voltage
                 10.1.2     Lightning current
                 10.1.3     Earth wire voltage drop
                 10.1.4     Power induction and earth potential rise
                 10.1.5     Mains power contact tests
       10.2     Coaxial port
                 10.2.1     Lightning voltage
                 10.2.2     Lightning current
                 10.2.3     Lightning currents flowing on the shield
                 10.2.4     Power induction and earth potential rise
       10.3     d.c. and a.c. dedicated power feeding ports
                 10.3.1     Lightning voltage
                 10.3.2     Lightning current
                 10.3.3     Power induction and earth potential rise
                 10.3.4     Mains power contact
       10.4     a.c. mains power port
                 10.4.1     Lightning voltage
                 10.4.2     Lightning current
                 10.4.3     Earth potential rise
                 10.4.4     Neutral potential rise
Annex A - Test schematics
        A.1     Introduction
        A.2     Equipment and test schematics
                  A.2.1     Equipment ports
                  A.2.2     Test schematic
        A.3     Test generators
        A.4     Waveform generation
        A.5     Test circuits including coupling, decoupling and powering networks
                  A.5.1     Symmetric pair ports
                  A.5.2     Coaxial ports
                  A.5.3     a.c. or d.c. dedicated power feed ports
                  A.5.4     Mains power ports
        A.6     Terminations
Appendix I - Explanations which illustrate test conditions
        I.1     Testing
                  I.1.1     General
                  I.1.2     Lightning surge tests
                  I.1.3     Power induction
                  I.1.4     Mains power contact
                  I.1.5     Terminations and SPDs on untested ports
                  I.1.6     Test connections for earthed and non-earthed equipment
        I.2     Range of lightning and power induction test levels
                  I.2.1     Lightning
                  I.2.2     Power induction test levels
        I.3     Relationship between Recommendation K.44 and other product/product family Recommendations
Appendix II - Supplementary information for manufacturers and operators
       II.1     Introduction
       II.2     Primary protection coordination
                 II.2.1     Primary protection does not operate
                 II.2.2     Primary protection does operate
                 II.2.3     Principles of coordination
       II.3     MDF voltage at the input of equipment
                 II.3.1     General
                 II.3.2     MDF earth wire voltage drop
                 II.3.3     Earth voltage drop test
       II.4     Current test on mains ports
       II.5     Earth and neutral potential rise
                 II.5.1     Background
                 II.5.2     Explanation