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ITU-T K.77 (07/2019)

Characteristics of metal oxide varistors for the protection of telecommunication installations

Recommendation ITU-T K.77 gives the basic requirements to be met by metal oxide varistors (MOVs) for the protection of power circuits and signal circuits of telecommunication installations from surges.

The purpose of this Recommendation is to provide technical guidelines for purchasers and manufacturers of MOVs to ensure their satisfactory operation in the applications for which they are intended.

This Recommendation is intended to be used for the harmonization of existing or future specifications issued by MOV manufactures, telecommunication equipment manufactures, administrations or network operators.

Citation:	https://handle.itu.int/11.1002/1000/13954
Series title:	K series: Protection against interference
Approval date:	2019-07-14
Provisional name:	K.var
Approval process:	AAP
Status:	In force
Maintenance responsibility:	ITU-T Study Group 5
Further details:	Patent statement(s) Development history

Ed.	ITU-T Recommendation	Status	Summary	Table of Contents	Download
2	K.77 (07/2019)	In force	here	here	here
1.2	K.77 (2009) Amd. 1 (12/2013)	Superseded	here	-	here
1.1	K.77 (2009) Cor. 1 (05/2011)	Superseded	here	here	here
1	K.77 (01/2009)	Superseded	here	here	here


ITU-T Supplement	Title	Status	Summary	Table of contents	Download
K Suppl. 3 (10/2015)	ITU-T K.20, K.21, K.45, K.82 – Additional criteria to protect telecommunication cabling during a power cross event	In force	here	here	here
K Suppl. 8 (11/2017)	Resistibility analysis of 5G systems	In force	here	here	here
K Suppl. 9 (05/2019)	5G technology and human exposure to radiofrequency electromagnetic fields	In force	here	here	here
K Suppl. 10 (11/2017)	Analysis of electromagnetic compatibility aspects and definition of requirements for 5G mobile systems	In force	here	here	here
K Suppl. 13 (12/2021)	Radiofrequency electromagnetic field (RF-EMF) exposure levels from mobile and portable devices during different conditions of use	In force	here	here	here
K Suppl. 14 (09/2019)	The impact of RF-EMF exposure limits stricter than the ICNIRP or IEEE guidelines on 4G and 5G mobile network deployment	In force	here	here	here
K Suppl. 16 (10/2022)	Electromagnetic field compliance assessments for 5G wireless networks	In force	here	here	here
K Suppl. 19 (09/2019)	Electromagnetic field (EMF) strength inside underground railway trains	In force	here	here	here
K Suppl. 29 (07/2022)	Electromagnetic field strength inside and outside of electric vehicles using wireless power transfer technology	In force	here	here	here

Title	Approved on	Download
Mitigation measures for telecommunication installations – Chapter 10	2006	here
Mitigation measures for telecommunication installations	2004	here
Earthing and bonding	2003	here
Guide to the use of ITU-T Publications produced by Study Group 5 aimed at achieving Electromagnetic Compatibility and Safety	2002	here
Earthing of telecommunication installations	1976	here

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ITU-T K.77 (07/2019)