IEC TS 61312-3:2000

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Definitions, abbreviations and symbols
4 Relevant threats - Lightning current parameters
5 Arrangement of SPDs within the Lightning Protection
      Zones concept
      5.1 Lightning protection zones
      5.2 Zone definitions
      5.3 Arrangement of SPDs at the zone interfaces
6 SPD performance requirements
      6.1 Transition from LPZ OA to LPZ 1
      6.2 Transition from LPZ OB and LPZ 1
      6.3 Transition from LPZ 1 to LPZ 2
7 Energy coordination
      7.1 General objective of coordination
      7.2 Fundamental coordination principles
             7.2.1 General
             7.2.2 Coordination of voltage limiting type
                      SPDs
             7.2.3 Coordination between voltage switching
                      type and voltage limiting type SPDs
             7.2.4 Coordination between voltage switching
                      type SPDs
      7.3 Basic coordination variants for protection
             systems
      7.4 Coordination method according to "let-through
             energy" (LTE)
      7.5 Coordination between an SPD and the equipment
             to be protected
             7.5.1 Selection of the SPD
             7.5.2 Place of installation
8 Summary
Annex A (informative) Examples for coordination between two
                      SPDs
      A.1 - Example of coordination between voltage limiting
            type SPDs
      A.2 - Example of coordination between voltage switching
            type SPD and voltage limiting type SPD
Annex B (informative) Influencing factors on the lightning
                      current distribution in a system to be
                      protected
      B.1 - Influencing the lightning current distribution
            in the low-voltage system
            B.1.1 - Influence of supplying cables
            B.1.2 - Influence of the transformer
            B.1.3 - Influence of the earthing system
            B.1.4 - Influence of parallel consumers
            B.1.5 - Simplified calculation method
            B.1.6 - Simplified calculation for SPD
                    requirements
Annex C (informative) Place of installation of SPD
      C.1 - Place of installation
Bibliography
Figure 1a - Example for dividing a structure into several
            LPZs and adequate bonding
Figure 1b - Example of the design of LPZs with a single SPD
            and a double-shielded cable
Figure 2 - Example for dividing a structure into several
           LPZs, with the appropriate bonding
Figure 3 - Basic model for energy coordination of SPDs in
           structures with a negligible low impedance of the
           CBN (see 8.1)
Figure 4a - Basic combination of two SPDs (voltage limiting
            type)
Figure 4b - Basic principle for energy coordination of two
            SPDs (voltage limiting type)
Figure 5a - Basic combination of two SPDs: voltage switching
            type (SPD 1) and voltage limiting type (SPD 2)
Figure 5b - Basic principle for energy coordination of two
            SPDs: voltage switching type and voltage
            limiting type
Figure 6a - Principle determination of decoupling inductance
            for energy coordination 10/350 mus and 0,1 kA/mu s
Figure 6b - Principle determination of decoupling inductance
            for energy coordination 10/350 mus and 0,1 kA/mu s
Figure 7 - Coordination principle according to variant I
           (voltage limiting type SPDs)
Figure 8 - Coordination principle according to variant II
           (voltage limiting type SPDs)
Figure 9 - Coordination principle according to variant III
           (voltage switching/voltage limiting type SPDs)
Figure 10 - Coordination principle according to variant IV
Figure 11 - LTE - Coordination method with standard pulse
            parameters
Figure A.1 - Circuit diagram for coordination between two
             voltage limiting type SPDs
Figure A.2 - Current/voltage characteristics of two SPDs
             (voltage limiting type)
Figure A.3 - Current and voltage characteristics at a
             combination of two voltage limiting type SPDs
Figure A.4 - Circuit diagram for coordination between
             voltage switching type SPD 1 and voltage
             limiting type SPD 2
Figure A.5 - Current and voltage characteristics at a
             combination of a SPD voltage switching type and
             a SPD voltage limiting type: SPD 1 not ignited
Figure A.6 - Current and voltage characteristics at a
             combination of a SPD voltage switching type and
             a SPD voltage limiting type: SPD 1 ignited
Figure A.7a - Circuit diagram
Figure A.7b - Current/voltage/energy characteristics for
              LDE = 8 muH: No energy coordination -
              10/350 mus
Figure A.7c - Current/voltage/energy characteristics for
              LDE = 10muH: Energy coordination - 10/350 mus
Figure A.7 - Example of energy coordination between voltage
             switching type SPD 1 and voltage limiting type
             SPD 2 for 10/350 mus
Figure A.8a - Circuit diagram
Figure A.8b - Current/voltage/energy characteristics for
              LDE = 10muH: No energy coordination -
              0,1 kA/mus
Figure A.8c - Current/voltage/energy characteristics for
              LDE = 12muH: Energy coordination - 0,1 kA/mus
Figure A.8 - Example of energy coordination between voltage
             switching type SPD 1 and voltage limiting type
             SPD 2 for 0,1 kA/mus
Figure B.1 - Basic model for the lightning current
             distribution
Figure B.2 - Circuit diagram of the basic model for the
             lightning current distribution
Figure B.3 - Lightning current distribution through the
             system dependent on the length of the cable
             (see Figure B.2)
Figure B.4 - Current distribution at cable length of 500 m
             (see Figure B.2)
Figure B.5 - Current distribution at cable length of 50 m
             (see Figure B.2)
Figure B.6 - Current distribution at different earthing
             impedances (transformer) Cable length: 100 m
             (see Figure B.2)
Figure B.7 - Model for lightning current distribution in the
             case of parallel consumers
Figure B.8 - Current distribution in the case of one parallel
             building (see Figure B.7)
Figure B.9 - Simplified calculation of partial lightning
             current into the power distribution system
Figure B.10 - Model for the lightning current distribution
              (see also Figure B.11)
Figure B.11 - Simplified equivalent circuit (see also Figure
              B.10)
Figure C.1 - Test circuit for simulation SPD and different
             loads connected by cables with different lengths
Figure C.2 - Voltage at SPD and load (1 m length of cable;
             see Figure C.1)
Figure C.3 - Voltage at SPD and load (10 m length of cable;
             see Figure C.1)
Figure C.4 - Voltage at SPD and load (100 m length of cable;
             see Figure C.1)
Table 1 - Lightning current parameters of the first stroke

Deals with the requirements of Surge Protective Devices (SPDs) standardized by IEC 61643-1. These SPDs are installed according to the Lightning Protection Zones concept given by IEC 61312-1.First, starting from primary relevant threats, gives instructions for the determination of the stress for individual SPDs.For SPDs installed within a complex system, it is admissible to divide the system into simple basic arrangements, observing the rules described. When the values and directions of the partial lightining currents flowing within the system are known, the appropriate SPDs can be selected.Also deals with basic questions of the energy coordination of SPDs among each other and between SPDs and the threat at the respective place of installation are to be considered for effective coordination. The proof of the coordination of SPDs installed in a system, is described briefly.