SANS 10142-1 - Surgetek - lightning protection, …

1 surge TechnologySANS10142-1/2003/ surge ArrestersSANS 10142 -1 : 2003 CODE OF PRACTICETHE WIRING OF PREMISESPart 1 : Low Voltage Installation4 ComplianceProof of Compliance (Sub clause ) The SABS safety markThe SABS approved performance Table ARRESTERSA pplicable standards surge arresters for LV systems --- SABS IEC 61643-1 SABS IEC 61643-1 - New since 1999 SABS 171- Withdrawn surge protectionSurge protection devices (SPDs) may be installed to protect an installationagainst overvoltage surges such as those due to switching operations orthose induced by atmospheric discharges ( lightning ).

2 Amdt 1 See annex L forthe installation of SPDs. Amdt 1 surge TechnologySANS10142-1/2003/ surge ArrestersAnnex LInstallation of surge protection devices (SPDs) into low-voltage volume to be protected is divided into LPZ in order to define the different levelsof exposure due to lightning surge currents and services that penetrate each zone shall be bonded at eachcrossover/penetration Transition from LPZ 0A to LPZ between LPZ 0A and LPZ 1 carry substantial lightning the interface between LPZ 0A and LPZ 1, Class I lightning currentSPDs are required. of such partial lightning currents, to which Class I SPDswill be exposed, are determined by the required protection level inaccordance with Table and sans IEC Transition from LPZ 0B to LPZ LPZ 0B, electromagnetic fields caused by lightning currents aredominant.

3 A direct stroke is the interface between LPZ 0B and LPZ 1, Class II overvoltage SPDsare required. (Class II SPDs should be tested in accordance withSANS 61643-1/IEC 61643-1 (SABS IEC 61643-1).)LPZ 0 LPZ 1 LPZ 2 LPZ 3 LPZ 3 Ref: SABS IEC 61312-1 surge TechnologySANS10142-1/2003/ surge ArrestersELIMINATING SOME CONFUSION In 99% of all cases conducting services traverse from LPZ 0A through LPZ0b to get to LPZ 1 In very few cases will conducting services only traverse from LPZ 0B to LPZ 1 Example of Transition from LPZ 0B to LPZ 1 Rolling SphereRolling SphereR = 20 mR = 20 mRolling SphereRolling SphereR = 20 mR = 20 mRolling SphereRolling SphereR = 20 mR = 20 mLPZ 0 ALPZ 0 ALPZ 0 BLPZ 0B LPZ 1 LPZ 1 Information Technology SystemInformation Technology SystemPower Supply SystemPower Supply

4 SystemBase Station123 GPSPP radioBTS antennaFeeder cableLPZ 0 ALPZ 0 ALPZ 2 LPZ 2 Bonding Bar 1 at the Boundary of LPZ 0A, 0 Band LPZ 1 LPZ 1 LPZ 1 CablesLocal Bonding Bar 2 at the Boundary ofLPZ 1 and LPZ 2 Bonding of Shield 2 Equipment Casing, Representing Shield 2 Earth Termination SystemLPZ 0 BLPZ 0 BLPZ 0 ALPZ 0 ABonding Bar 1 at the Boundary of LPZ 0 Band LPZ 1 CablesSurge TechnologySANS10142-1/2003/ surge ArrestersThe Modified Clause Transition from LPZ 0 to LPZ At the interface between LPZ 0 and LPZ 1,Class I + Class II SPDs are do we need to Know about SPDs ?

5 TYPE of SPDT here are basically TWO types of Current lightning surge Of SPD sSPD s are divided into Classes as per SABS IEC: 61643-1 and 61312-1 Class I - lightning Current ArresterClass II - Overvoltage ArresterClass III - Overvoltage Requirements Class I - Type SPD (Ref: IEC 60364-5-534) the value of Iimp for SPD s connected betweenPhase and Neutral shall not be less than kA (10/350) .. for SPD s connected between Neutral and PE - Iimp shall not be less than 25 kA (10/350) and 50 kA (10/350) for Three Phase Minimum Requirements Class II - Type SPD (Ref: IEC 60364-5-534) the value of Isn for SPD s connected betweenPhase and Neutral shall not be less than 5 kA (8/20) for SPD s connected between Neutral and PE- Isn shall not be less than 10 kA (8/20) and 20 kA (8/20) for Three Phase systemsSurge TechnologySANS10142-1/2003/ surge WAVE SHAPES ?

6 I the Wave Shape is 10/350 micro seconds ( s) II the Wave Shape is 8/20 micro seconds ( s) III the Wave Shape is 8/20 micro seconds ( s)waveform s10/3508/20i max. kA10010Q J/ 1060,4 103 StandardSABS IEC SABS IEC 61024-1-1 61024-1-1 Comparison of lightning Test Currents(kA)200 s350 s600 s800 s1000 st ( s)111180 s20 kA40 kA60 kA80 kA100 kA50 kA22221122 Amplitude Comparison of Equally Charged lightning Currents with Waveforms 10/350 s and 8/20 / / Current (8/20 s) in kALightning Impulse Current(10/350 s) in kASurge TechnologySANS10142-1/2003/ surge I type SPD - The most commonly used types Class II type SPD - The mostly commonly used typeare MOV (Metal Oxide Varistor)

7 SPDs shall comply with the requirements of sans IEC 61643-1 andshall have been tested as Class II devicesb) SPDs in the main distribution board shall be at least Class II devices;c) except for voltage switching (gapped) type, each Class IIvoltage-limiting SPD shall be equipped with a thermal disconnectingmechanism and visual indication that shows end of life; surge protectionWhere a surge protection device is installed, it shall be installed afterthe main switch (see annex L). Amdt Power and telecommunication lines should enter the building orstructure in close proximity and NOT on opposite sides of the buildingor For total protection , SPDs should be installed on all conductiveservices that enter or leave a building or a structure by the installer ofsuch - Characteristic of 275 V - MOV 10020080040010-560010002000400010-410-31 0-210-1100101102103104105 (A)U (V) surge TechnologySANS10142-1/2003/ surge Arresters What is the right protection level or value?

8 (Clamping or ResidualVoltage) According to the requirements of the insulation coordination in powerinstallations (see IEC 60664-1) and the surge immunity of equipment to beprotected, it is necessary to keep the voltage protection levels of the SPDsbelow a maximum value of the surge immunity level of the equipment. If theimmunity against damage is not known, component immunity levels as inSANS 61000-4-5/IEC 61000-4-5 (SABS IEC 61000-4-5) shall be The impulse withstand levels are divided into categories as given in with overvoltage limits listed for standard 230/400 V three-phasefour-wire systems as in IEC SPDs must be sans 61643-1 external lightning protection is required you need Class I &Class II or combination Class II SPDs with disconnection mechanism and without disconnection device can only be used with Use back-up fuse protection as per the manufactures wire sizes as per the manufactures connecting wires as short as possible < 500 mindful of down stream SPD

9 Expert advise if you are unsur