IEC_81_229_INF.pdf

81/229/INFFor IEC use only2003-07-25INTERNATIONAL ELECTROTECHNICAL COMMISSIONTECHNICAL COMMITTEE No.81:LIGHTNING PROTECTIONLiaison with other TC/SC and with others organisationsJoint task force with SC 77B:“To study the fiture use of surge simulator for SPD testing”Progressreport(to be discussed under draft agenda item 12.1 at the forthcoming TC 81 meeting to be held in Palma deMallorca 29th and 30th September 2003)PROPOSALS FOLLOWING THE MEETING OF JTF 778 TC 81 HELD IN NUERNBERG,MARCH 5 2002(report submitted by Michael Hopkins)1)AMENDMENT TO 61000-4-5 ANNEX B12.2.2 System level immunityThe test carried out in the laboratory refers to an EUT,but immunity at the EUT does not necessarily assurethe immunity of a larger system which contains that EUT.In order to ensure system level immunity,a test atthe system level is recommended to simulate the real installation.This simulated installation shall becomprised not only of individual EUTs,but must shall also include protective devices(Surge ProtectiveDevices-SPDs)and the real1ength and type of the interconnection lines normally used.all of which canaffect the overall system protection level.The simple addition of an external SPD that is not coordinated withother internal SPDs,might have no effect,might reduce the effect on the overall system protection,or mightimprove overall system protection.Additional information can be found in IEC Surge Protective DevicesStandards.IEC 61643 and IEC 61312(Protection against lightning electromagnetic impulse).This test is aimed at simulating as closely as possible the installation conditions in which the EUT or EUTsare intended to function.In a real installation,higher voltage levels can be applied.but the surge energy will be limited by the installedprotective devices in accordance with their current-limiting characteristics.The system level test is also intended to show that secondary effects produced by the protective devices(change of waveform,mode,amplitude of voltages or currents)do not cause unacceptable effects on theEUT.2)PROPOSED ADDITION TO IEC 61643-1The next release should ensure that the combination wave generator specifications far testing Class IIISPDs be aligned with IEC 61000-4-5.Because of the differences in tolerance specified in IEC 61000-4-5and IEC 61643-1,combination wave generators that m the waveform requirements far IEC 61000-4-5 donot necessarily meet the requirements of IEC 61643-1.The following changes to IEC 61643-1 would bring the tolerances into line with IEC 61000-4-5:Page 53.section 7.1.4 Class III combination wave test.Change the tolerances for open-circuit voltage and short circuit current to be:The tolerances on the open-circuit voltage Uoc shall be the following:-peak value+/-1 0%(currently+1-3%in)-front time/-30%-time to half value+/-20%2 81/229/INFThe tolerances on the short-circuit current shall be the following:-peak value+/-10%-front time+/-20%(currently+/-10%)-time to half value+/-20%(currently+J-10%)Page 55.Table 4-Tolerances on Cl3SS 111 test waveform parameters must be modified in accordance withthe above:Open-circuitShort-circuitVoltage Uoccurrent IscPeak Values+1-10%Uoc/2 ohms+/-10%Front time1.2+/-30%8+/-20%Time to half value50+/-20%20+/-20%3)PROPOSED AMENDMENT TO IEC 61643-12A statement needs to be added 10 IEC 61643-12 similar to the statement in IEC 61000-4-5 Annex B,paragraph 12.2.2 referring to the possible effects of adding an external SPD to an EUT and the necessity farsystem level tasting to ensure SPD coordination._