IEC_60364-4-44_64_1341_CD.pdf

64/1341/CDCOMMITTEE DRAFT(CD)IEC/TC or SC:TC 64Project numberIEC 60364-4-44,A2,Ed.1Title of TC/SC:Electrical installations and protection againstelectrical shockDate of circulation2003-10-03Closing date for comments2004-01-09Also of interest to the following committees Supersedes documents64/1274/CD and 64/1318/CCFunctions concerned:Safety EMC Environment Quality assuranceSecretary:Dipl.-Ing.R.Pelta(Germany)E-mail:THIS DOCUMENT IS STILL UNDER STUDY AND SUBJECT TOCHANGE.IT SHOULD NOT BE USED FOR REFERENCE PURPOSES.RECIPIENTS OF THIS DOCUMENT ARE INVITED TO SUBMIT,WITHTHEIR COMMENTS,NOTIFICATION OF ANY RELEVANT PATENTRIGHTS OF WHICH THEY ARE AWARE AND TO PROVIDESUPPORTING DOCUMENTATION.Title:Amendment 2 to IEC 60364-4-44,Ed.1:Electrical installations of buildings-Part 4-44:Protectionfor safety-Protection against voltage disturbances and measures against electromagneticinfluences-Clause 444:Measures against electromagnetic influences(Titre):Introductory noteFORM CD(IEC)2002-05-14Copyright 2003 International Electrotechnical Commission,IEC.All rights reserved.It ispermitted to download this electronic file,to make a copy and to print out the content for the solepurpose of preparing National Committee positions.You may not copy or mirror the file orprinted version of the document,or any part of it,for any other purpose without permission inwriting from IEC.XXX IEC:200X 2 64/1341/CDFOREWORDThis amendment has been prepared by IEC technical committee No.64:Electrical installations andprotection against electric shock.The text of this amendment is based on the following documents:FDISReport on votingXX/XX/FDISXX/XX/RVDFull information on the voting for the approval of this amendment can be found in the report on votingindicated in the above table.The committee has decided that the contents of the base publication and its amendments will remainunchanged until 20XX.At this date,the publication will bereconfirmed;withdrawn;replaced by a revised edition,oramended._Clause 440:INTRODUCTION,page 9Substitute the paragraph beginning with:“Introduction IEC 60364-4-444”and ending before thesentence“Clause 445.”by the following text:Electromagnetic influences can disturb or damage information technology systems or equipment andequipment with electronic components or circuits.NOTE-Information technology equipment includes all forms of electrical and electronic business equipment andtelecommunications equipment(for more information regarding the term“information technology equipment“seethe scope of IEC 60950-1).Examples of equipment and installations to which this clause may apply are:-telecommunication and data communication or data processing equipment,or installations using signallingwith earth return in internal connections and external connections to a building;-d.c.power supply networks serving information technology equipment inside a building;-private automatic branch exchange(PABX)equipment or installations;-local area networks(LAN);-fire alarm systems and intruder alarm systems;-building management services,e.g.direct digital control systems;-systems for computer-aided manufacturing(CAM)and other computer-aided services.If a lightning protection system(LPS)is installed measures are necessary for electromagnetic compatibility(EMC)reasons.To ensure EMC by measures of equipotential bonding consideration should be taken regardingthe coordination of LPS measures and measures for protection against electric shock.Currents due to lightning,switching operations,short circuits and other electromagnetic phenomenacan cause overvoltages and electromagnetic interference.These effects appear:-where large metal loops exist1);and;-where different electrical wiring systems are installed on different routes,e.g.for power1)Equipotential bonding systems,structural metalwork or pipe systems for non-electrical supplies,e.g.for water,gas,heating or air conditioning,can create such induction loops.XXX IEC:200X 3 64/1341/CD supply and for signalling information technology equipment within a building;and-where circuits enter or leave the building.The value of the induced voltage depends on the rate of change(di/dt)of the interference current,and on the size of the loop.Power cables carrying large currents with a high rate of change of current(di/dt)(e.g.the startingcurrent of lifts or currents controlled by rectifiers)can induce overvoltages in cables of informationtechnology systems,which can interfere with or cause damage to information technology or similarsensitive electrical equipment.In or near rooms for medical use,electric or magnetic fields of electrical installations can interferewith medical electrical equipment.Equipotential bonding systems should not carry significant load currents during normal operation.The following requirements are intended to improve interference-free operation of data processingand other equipment.When interference occurs additional suitable measures may be necessary(e.g.blocking-chokes orfrequency filters).Pa