IEC_81_228_INF.pdf

81/228/INFFor IEC use only2003-07-25INTERNATIONAL ELECTROTECHNICAL COMMISSIONTECHNICAL COMMITTEE No.81:LIGHTNING PROTECTIONLiaison with other TC/SC and with others organisations(to be discussed under draft agenda item 12 at the forthcoming TC 81 meeting to be held in Palma deMallorca 29th and 30th September 2003)1)SC 37 AThe report has been prepared by the Liaison Member between SC 37A and TC 81,Mr.Alain ROUSSEAU.Since the last TC81 meeting a few things happened in SC37A:WG 5:“Power SPD product testing”:After publication of IEC 61643-1 and its Amendment A1,this WG is working hard to produce a secondAmendment correcting some mistakes,bringing some new data and introducing new sentences/tables whichwill still improve coordination both with TC 64(TOV,)and TC 81(introduction of W/R for the Class I test,.)It is also working on the future revision of the standard in order to simplify the use of it as well as to make aclear distinction between mandatory test,optional tests and tests dedicated to one technology only.Following the question raised by TC 81 to introduce a test to check coordination,the WG arrive to theconclusion that such a test is not possible as the network condition greatly differs from one case to another.Some guidance will be introduced in the application guide.WG 3:“Power SPD application”:After publication of IEC 61643-12,this WG is working on the preparation of the Amendment 1.Purpose of A1is to simplify the text and to be more practical as well as introducing a new text layout as proposed by Italyand Austria.In addition,modification of the text to be more in line with new TC 64 requirements areintroduced.Regarding the coordination between TC 81 and SC37A on that field it appears that the new document81/212/CD is not fully in line both with TC 64 and SC37A.A letter from SC 37A Chairman/Secretary to TC 81Chairman/Secretary has been sent to raise that point.WG4:“Telecom SPD application”:After publication of 61643-21,this WG is preparing both an first Amendment for the standard as well as anapplication guide which is a the CDV stage.2)TC 64No meetings TC 64/TC 81 has been held since the TC 81 Beijing meeting.2 81/228/INF3)UIT/SG 5The report has been prepared by the Liaison Member between UIT/SG 5 and TC 81,Mr.Ahmed ZEDDAM.Since the last meeting of TC 81 the SG 5 met three times:On December 2002 in Geneva,on February 2003in Sydney(Australia)and on June 2003 in Camogli(Italy).Study Group 5(SG 5)“Protection against electromagnetic effects”of the ITU-T(InternationalTelecommunication Union-Telecommunication Sector)plans its activity for a Study Period which has aduration of four years.In this Study Period(2001-2004),SG 5 has nominated A.Zeddam as the liaison member between SG 5 andIEC TC 81 and has located the work on lightning protection of telecommunication installations underQuestion 5“Lightning protection of fixed,mobile and wireless system”.During its first meeting(December 2000),SG5 has approved the following two Recommendations:-Recommendation K.46“Protection of telecommunication lines using paired conductors against lightninginduced surges”;-Recommendation K.47“Protection of telecommunication lines using metallic conductors against directlightning discharges”These two Recommendations are based on the previous IEC standard 61663-2.Considering the newnumbering of IEC 62305-Series and the changes introduced in the risk assessment methodology,a liaisonstatement has been produced by the convenor of WG 10 in order to inform ITU-T/SG 5 about the work ofIECTC 81.During the last meeting held in Italy on June 2003,SG 5 has approved the following Recommendations:a)New Recommendation K57“Protection against lightning effects on radio base stations”This Recommendation provides a quantitative procedure in order to protect radio base stations(RBS)forwireless access network against lightning discharges.The level of protection is based on the tolerablefrequency of damage that is assigned to the RBS by the operator,considering the consequences of serviceinterruption and loss of equipment.The RBS covered by this Recommendation is made up of a shelter orsmall building to house the equipment and a nearby tower to hold the antennas.The protection proceduresincludes earthing,bonding,shielding and installation of surge protective devices(SPD).In order to estimate the need of protection of a RBS against lightning,the user shall determine the tolerablefrequency of damage(Ft)and to calculate the frequency of lightning strikes to the antenna tower of the RBS(Fa)and the housing(Fd).If Fa+Fd is smaller than Ft,then the direct lightning discharge is not a phenomenaof prime importance for the RBS and it can be treated as an ordinary remote electronic site,which is underthe scope of Recommendation K.35.However,if Fa+Fd is greater than Ft,then the RBS will need protectionagainst direct lightning discharges.The implementation of such protection accordingly with thisRecommendation will also provide protection against the lightning