1 Scope
2 References
3 Definitions, abbreviations and
symbols
3.1 Definitions
3.2 Abbreviations and
acronyms
3.3 Symbols
4 Overvoltage and overcurrent
conditions
5 Resistibility requirements
5.1 Basic resistibility
requirement
5.2 Enhanced resistibility requirement
6 Equipment boundary
7 Test conditions
7.1 Interface ports
7.1.1 Port classification
7.1.2 Interface
ports
7.2 Test types
7.2.1 Transverse/differential
7.2.2 External
port to earth
7.2.3 External
port to external port
7.2.4 Internal
port to earth
7.3 Test conditions
7.4 Test schematics
8 Protection coordination
8.1 General
8.2 Lightning
8.2.1
Primary SPDs with a switching
characteristic
8.2.2
Primary SPDs with a clamping
characteristic
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
8.5 Selection of the
agreed primary protector
9 Acceptance criteria
10 Tests
10.1 External symmetric
pair port
10.1.1 Lightning
voltage
10.1.1.1 Single pair
10.1.1.2 Multiple pairs/ports
10.1.2 Lightning
current
10.1.3 Power
induction and earth potential rise
10.1.4 Mains
power contact tests
10.2 External coaxial port
10.2.1 Lightning
voltage
10.2.2 Lightning
current differential
10.2.3 Lightning
current shield test
10.2.4 Earth
potential rise
10.3 External 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 External a.c. mains power port
10.4.1 Lightning
voltage
10.4.2 Earth
potential rise
10.4.3 Neutral
potential rise
10.5 Internal ports
10.5.1 Unshielded
cable
10.5.2 Shielded
cable
10.5.3 Floating
d.c. power interface
10.5.4 Earthed
d.c. power interface
Annex A – Test schematics
A.1 Introduction
A.2 Equipment
A.2.1 Equipment
ports
A.2.2 Equipment
type
A.2.3 Protection
type
A.2.4 Equipment
conditions and states
A.3 Test generators
A.4 Waveform generation
A.5 Powering, coupling,
decoupling and terminations
A.5.1 General
A.5.2 Tested
ports
Page
A.5.2.1 External
symmetric pair
A.5.2.2 External coaxial cable port
A.5.2.3 External dedicated power feed port
A.5.2.4 Mains ports
A.5.2.5 Internal unshielded cable port
A.5.2.6 Internal shielded cable port
A.5.2.7 Internal d.c. power interface
A.5.3 Untested
ports
A.5.3.1 External symmetric pair
A.5.3.2 External coaxial
cable port
A.5.3.3 External dedicated power feed port
A.5.3.4 Mains ports
A.5.3.5 Internal unshielded cable port
A.5.3.6 Internal shielded cable port
A.5.3.7 Internal d.c. power interface
A.5.4 Protection
elements
A.5.4.1 External symmetric pair
A.5.4.2 External coaxial cable port
A.5.4.3 Dedicated power feed port
A.5.4.4 Mains power port
A.6 Test schematics for
different types of ports
A.6.1 Symmetric pair
ports
A.6.2 Coaxial
ports
A.6.3 a.c. or
d.c. dedicated power feed ports
A.6.4 Mains
power ports
A.6.5 Internal
cable ports
A.6.6 d.c. power
ports
A.6.7 Ethernet ports
Appendix I – Explanations that illustrate test conditions
I.1 Testing
I.1.1 General
I.1.2 Lightning
surge tests
I.1.2.1 Inherent test
I.1.2.2 Secondary protector coordination test
I.1.2.3 Primary protector coordination test
I.1.2.4 Uc(max) test
I.1.2.5 Effects for greater than Uc(max)
I.1.3 Power
induction
I.1.3.1 Inherent test
I.1.3.2 Secondary protector coordination test
I.1.3.3 Secondary protector operating test
I.1.3.4 Minimum energy to operate PTCs
I.1.3.5 Primary protector coordination test
I.1.3.6 Ua.c.(max) test
I.1.4 Mains power contact
I.1.5 Rationale
for test conditions
I.1.5.1 Port to port and port to earth testing
I.1.5.2 Terminations and SPDs on untested ports
I.1.6 Decoupling
networks
I.1.6.1 Decoupling inductance
I.1.6.2 Effect of inductance and resistance decoupling elements on digital
circuits
I.1.7 Mains port
testing
I.2 Range of
lightning and power induction test levels
I.2.1 Lightning
I.2.1.1 Inherent test levels
I.2.1.2 Coordination test levels
I.2.2 Power
induction test levels
I.2.2.1 Inherent test levels
I.2.2.2 Inherent/coordination test levels
I.3 Relationship
between this Recommendation and other product or 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.2.4 Coordination
testing of switching and clamping SPDs
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.3.3.1 United Kingdom's example of earth voltage drop problem
II.3.3.2 Australian example of an earth voltage drop problem at customer
premises
II.3.3.3 Australian example of an earth voltage drop problem at a
telecommunication centre
II.3.3.4 Possible test for resistibility to earth voltage drop
II.4 Current test on mains
ports
Page
II.5 Earth and neutral potential rise
II.5.1 Background
II.5.2 Explanation
II.5.2.1 Earth potential rise
II.5.2.2 Neutral potential rise
II.5.2.3 Currents that may flow through equipment
II.5.2.4 Surge transfer
II.6 Special resistibility
requirements
II.7 Equipment fire in
equipment complying with Recommendation ITU-T K.21
II.8 Ethernet
II.8.1 Insulation
II.8.2 Ethernet
ports
II.8.3 Ethernet
overvoltages
II.8.3.1 Lightning
II.8.3.2 Power fault
II.8.3.3 Unscreened twisted pair (UTP) and screened twisted pair (STP)
cables
II.8.4 SPCs and
SPDs
II.8.5 Insulation
barriers in series
II.8.6 Increasing
the rated impulse voltage
II.8.6.1 In-line higher voltage insulation barrier
II.8.6.2 Ethernet SPD
Bibliography