K.21

ITU-T : Publications : Recommendations : K Series

• K.1[Withdrawn] Connection to earth of an audio-frequency telephone line in cable Deleted after its content became technically out of date
• K.2[Withdrawn] Protection of repeater power-feeding systems against interference from neighbouring electricity lines Deleted after its content became technically out of date
• K.3 [Withdrawn] Interference caused by audio-frequency signals injected into a power distribution network Deleted after its content became technically out of date
• K.4 [Withdrawn] Disturbance to signalling Deleted after its content became technically out of date
• K.5 Joint use of poles for electricity distribution and for telecommunications
• K.6 Precautions at crossings
• K.7 Protection against acoustic shock
• K.8 Separation in the soil between telecommunication cables and earthing system of power facilities
• K.9 Protection of telecommunication staff and plant against a large earth potential due to a neighbouring electric traction line
• K.10 Low frequency interference due to unbalance about earth of telecommunication equipment
• K.11 Principles of protection against overvoltages and overcurrents
• K.12 Characteristics of gas discharge tubes for the protection of telecommunications installations
• K.13 Induced voltages in cables with plastic-insulated conductors
• K.14 Provision of a metallic screen in plastic-sheathed cables
• K.15 [Withdrawn] Protection of remote-feeding systems and line repeaters against lightning and interference from neighbouring electricity lines
• K.16 [Withdrawn] Simplified calculation method for estimating the effect of magnetic induction from power lines on remote-fed repeaters in coaxial pair telecommunication systems Rec. K.16 was withdrawn because it deals only with calculation methods contained in the "Directives - Volume II: Calculating induced voltages and currents in practical cases" without giving any limit
• K.17 [Withdrawn] Tests on power-fed repeaters using solid-state devices in order to check the arrangements for protection from external interference
• K.18 Calculation of voltage induced into telecommunication lines from radio station broadcasts and methods of reducing interference
• K.19 Joint use of trenches and tunnels for telecommunication and power cables
• K.20 Resistibility of telecommunication equipment installed in a telecommunication centre to overvoltages and overcurrents
• K.21 Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents
• K.22 [Withdrawn] Overvoltage resistibility of equipment connected to an ISDN T/S bus
• K.23 Types of induced noise and description of noise voltage parameters for ISDN basic user networks
• K.24 Method for measuring radio-frequency induced noise on telecommunications pairs
• K.25 [Withdrawn] Protection of optical fibre cables This Recommendation was deleted on 2013-01-25 since its requirements have been incoroporated in revised Rec ITU-T K.47 (05/2012)
• K.26 Protection of telecommunication lines against harmful effects from electric power and electrified railway lines
• K.27 Bonding configurations and earthing inside a telecommunication building
• K.28 Parameters of thyristor-based surge protective devices for the protection of telecommunication installations
• K.29 Coordinated protection schemes for telecommunication cables below ground
• K.30 [Withdrawn] Self-restoring overcurrent protectors
• K.31 [Withdrawn] Bonding configurations and earthing of telecommunication installations inside a subscriber's building
• ITU-T K.31 was deleted on 2008-08-09 after the incorporation of the relevant part of this Recommendation in ITU-T K.73 (2008)
• K.32 [Withdrawn] Immunity requirements and test methods for electrostatic discharge to telecommunication equipment - Generic EMC Recommendation
• The content of this Recommendation has been superseded by ITU-T K.43 (1998) and K.48 (2000)
• K.33 [Withdrawn] Limits for people safety related to coupling into telecommunications system from a.c. electric power and a.c. electrified railway installations in fault conditions ITU-T K.33 was deleted on 2008-08-09 after the incorporation of the relevant information contained in this Recommendation into the revised the Directives Volume VI (2008)
• K.34 Classification of electromagnetic environmental conditions for telecommunication equipment - Basic EMC Recommendation
• K.35 Bonding configurations and earthing at remote electronic sites
• K.36 Selection of protective devices
• K.37 Low and high frequency EMC mitigation techniques for telecommunication installations and systems - Basic EMC Recommendation
• K.38 Radiated emission test procedure for physically large systems
• K.39 Risk assessment of damages to telecommunication sites due to lightning discharges
• K.40 Protection against LEMP in telecommunications centres
• K.41 [Withdrawn] Resistibility of internal interfaces of telecommunication centres to surge overvoltages
• K.42 Preparation of emission and immunity requirements for telecommunication equipment - General principles
• K.43 Immunity requirements for telecommunication network equipment
• K.44 Resistibility tests for telecommunication equipment exposed to overvoltages and overcurrents - Basic Recommendation
• K.Imp44 Implementors' Guide for Recommendation ITU-T K.44
• K.45 Resistibility of telecommunication equipment installed in the access and trunk networks to overvoltages and overcurrents
• K.46 Protection of telecommunication lines using metallic symmetric conductors against lightning-induced surges
• K.47 Protection of telecommunication lines against direct lightning flashes
• K.48 EMC requirements for telecommunication equipment - Product family Recommendation
• K.49 Test requirements and performance criteria for voice terminal telephones subject to disturbance from digital mobile telecommunications systems
• K.50 Safe limits of operating voltages and currents for telecommunication systems powered over the network
• K.51 Safety criteria for telecommunication equipment
• K.52 Guidance on complying with limits for human exposure to electromagnetic fields
• K.53[Withdrawn] Values of induced voltages on telecommunication installations to establish telecom and a.c. power and railway operators responsibilities ITU-T K.53 was deleted on 2008-08-09 after the incorporation of the relevant information of this Recommendation in ITU-T K.68 (2008)
• K.54 Conducted immunity test method and level at fundamental power frequencies
• El título español fue cambiado por un erratum el 09/08/2002
• K.55 Overvoltage and overcurrent requirements for insulation displacement connectors (IDC) terminations
• K.56 Protection of radio base stations against lightning discharges
• K.57 Protection measures for radio base stations sited on power line towers
• K.58 EMC, resistibility and safety requirements and guidance for determining responsibility under co-located information and communication technology installations
• K.59 EMC, resistibility and safety requirements and procedures for connection to unbundled cables
• K.60 Emission levels and test methods for wireline telecommunication networks to minimize electromagnetic disturbance of radio services
• K.61 Guidance on measurement and numerical prediction of electromagnetic fields for compliance with human exposure limits for telecommunication installations
• K.62 System level radiated emissions compliance using mathematical modelling
• K.63 Maintaining the suitability of production telecommunications equipment to its intended electromagnetic environment
• K.64 Safe working practices for outside equipment installed in particular environments
• K.65 Overvoltage and overcurrent requirements for termination modules with contacts for test ports or surge protective devices
• K.66 Protection of customer premises from overvoltages
• K.67 Expected surges on telecommunications and signalling networks due to lightning
• K.68 Operator responsibilities in the management of electromagnetic interference by power systems on telecommunication systems
• K.69 Maintenance of protective measures
• K.70 Mitigation techniques to limit human exposure to EMFs in the vicinity of radiocommunication stations
• K.71 Protection of customer antenna installations
• K.72 Protection of telecommunication lines using metallic conductors against lightning - Risk management
• K.73 Shielding and bonding for cables between buildings
• K.74 Electromagnetic compatibility, resistibility and safety requirements for home network devices
• K.75 Classification of interface for application of standards on resistibility and safety of telecommunication equipment
• K.76 EMC requirements for telecommunication network equipment (9 kHz-150 kHz)
• K.77 Characteristics of metal oxide varistors for the protection of telecommunication installations
• K.78 High altitude electromagnetic pulse immunity guide for telecommunication centres
• K.79 Electromagnetic characterization of the radiated environment in the 2.4 GHz ISM band
• K.80 EMC requirements for telecommunication network equipment (1 GHz - 6 GHz)
• K.81 High-power electromagnetic immunity guide for telecommunication systems
• K.82 Characteristics and ratings of solid-state, self-restoring overcurrent protectors for the protection of telecommunications installations
• K.83 Monitoring of electromagnetic field levels
• K.84 Test methods and guide against information leaks through unintentional electromagnetic emissions
• K.85 Requirements for the mitigation of lightning effects on home networks installed in customer premises
• K.86 Method for measuring longitudinal conversion loss (9 kHz - 30 MHz)
• K.87 Guide for the application of electromagnetic security requirements - Overview
• K.88 EMC requirements for next generation network equipment
• K.89 Protection of persons inside a structure using telecommunication services provided by metallic conductors against lightning - Risk management
• K.90 Evaluation techniques and working procedures for compliance with exposure limits of network operator personnel to power-frequency electromagnetic fields
• K.91 Guidance for assessment, evaluation and monitoring of human exposure to radio frequency electromagnetic fields
• K.92 Conducted and radiated electromagnetic environment in home networking
• K.93 Immunity of home network devices to electromagnetic disturbances
• K.94 Mutual disturbance test method for evaluating performance degradation of converged terminal devices
• K.95 Surge parameters of isolating transformers used in telecommunication devices and equipment
• K.96 Surge protective components: Overview of surge mitigation functions and technologies
• K.97 Lightning protection of distributed base stations
• K.98 Overvoltage protection guide for telecommunication equipment installed in customer premises
• K.99 Surge protective component application guide - Gas discharge tubes
• K.100 Measurement of radio frequency electromagnetic fields to determine compliance with human exposure limits when a base station is put into service
• K.101 Shielding factors for lightning protection
• K.102 Parameters of fixed-voltage thyristor overvoltage protector components used for the protection of telecommunication installations
• K.103 Surge protective component application guide - Silicon PN junction components
• K.104 Method for identifying the transfer potential of the earth potential rise from high or medium voltage networks to the earthing system or neutral of low voltage networks
• K.105 Lightning protection of photovoltaic power supply systems feeding radio base stations
• K.106 Techniques to mitigate interference between radio devices and cable or equipment connected to wired broadband networks and cable television networks
• K.107 Method for determining the impedance to earth of earthing systems
• K.108 Joint use of poles by telecommunication and solidly earthed power lines
• K.109 Installation of telecommunication equipment on utility poles
• K.110 Lightning protection of the dedicated transformer for radio base station
• K.111 Protection of surrounding structures of telecommunication towers against lightning
• K.112 Lightning protection, earthing and bonding: practical procedures for radio base station
• K.113 Generation of radiofrequency electromagnetic fields (RF-EMF) level maps
• K.114 Electromagnetic compatibility requirements and measurement methods for digital cellular mobile communication base station equipment
• K.115 Mitigation methods against electromagnetic security threats
• K.116 EMC requirements and test methods for radio telecommunication terminal equipment
• K.Sup1 ITU-T K.91 - Guide on electromagnetic fields and health
• K.Sup2 ITU-T K.52 - Calculator for equivalent isotropic radiated power as described in Recommendation ITU-T K.52
• K.Sup3 Additional criteria to protect telecommunication cabling during a power cross event
• K.Sup4 Electromagnetic field (EMF) considerations in smart sustainable cities

ITU-T : Publications : Recommendations : K Series : K.21

ITU-T K.21 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (06/2020)

SERIES K: PROTECTION AGAINST INTERFERENCE

Resistibility of telecommunication equipment installed in customer premises to overvoltages and overcurrents

雷击测试 K.21标准与GB 17626.5 差异

通讯产品在做认证时，常会遇到Surge这项测试， 如K.21通信产品雷击测试与GB 17626.5普通通用产品雷击测试。

就以10/700us的Surge测试来说，在IEC 61000-4-5和ITU-T K.21有着同样的上升下降雷击波形，但在做测试时，却不能相互取代。其主要的原因是其雷击输出端的不同，

因为是要搭配不同纵向、横向的测试模式，所以会因不同标准而设计不同的测试仪器。再则，IEC 61000-4-5的要求只到4kV surge，ITU-T K.21却常被要求到6kV surge，甚至还有15kV的需求。

更多关于K.21雷击请参阅

https://www.emc.wiki/thread-4209-1-1.html