PD IEC/TR 62066:2002

Foreword
1 Scope
2 Reference documents
3 Definitions
4 Overvoltages in low-voltage systems
5 Lightning overvoltages
   5.1 General
   5.2 Origin of lightning surge overvoltages
   5.3 Lightning surges transferred from MV systems
   5.4 Surges caused by direct flash to LV lines
   5.5 Lightning surges induced into LV systems
   5.6 Examples of induced overvoltages
   5.7 Overvoltages caused by flashes to the
        structures or in close vicinity
   5.8 Recapitulation on lightning overvoltages
6 Switching overvoltages
   6.1 General
   6.2 Operation of circuit-breakers and switches
   6.3 Operation of fuses
   6.4 Frequency of occurrence
   6.5 Interactions with surge-protective devices
   6.6 Recapitulation on switching overvoltages
7 Temporary overvoltages
   7.1 General
   7.2 Magnitude of temporary overvoltages due to MV
        and LV faults
   7.3 Temporary overvoltages due to defects in the LV
        electrical installation
   7.4 Probability of occurrence and severity of harm
   7.5 Recapitulation on temporary overvoltage
8 System interaction overvoltages
   8.1 General
   8.2 Interaction between power system and communications
        system
   8.3 Other interactions
   8.4 Recapitulation on system interactions
9 Observations on surge overvoltages and failure rates
   9.1 General
   9.2 Using field failure data
   9.3 Recapitulation of observations on failure rates
10 Considerations on system outage/equipment failure/fires
   10.1 General
   10.2 Avoiding interference in system operation
   10.3 Preventing permanent damage
   10.4 Costs of surge-related interruptions and failures
   10.5 Recapitulation on outages and failures
11 Considerations on the use of surge protection
   11.1 General
   11.2 Power system configuration
   11.3 Types of installation
   11.4 Occurrence of surges
   11.5 SPD disconnector
   11.6 Risk assessment
   11.7 Recapitulation on the need for surge protection
12 Surge protection application
   12.1 General
   12.2 Surge protective devices in power distribution
        systems
   12.3 Basic system characteristics for SPD selection
   12.4 Considerations for installation of SPDs
   12.5 Coordination among SPDs and with equipment to be
        protected
   12.6 Recapitulation on surge protection application
Annex A (informative) Complementary information on
        lightning-related overvoltages
Annex B (informative) Switching overvoltages
Annex C (informative) Complementary information on
        temporary overvoltages
Annex D (informative) Complementary information on
        system interaction overvoltages
Annex E (informative) Complementary information on SPD
        application
Annex F (informative) Avoiding overvoltages through
        good practice for earthing and cabling
Bibliography
Figures
Tables

Describes a general overview on the different kinds of surge over-voltages that can occur on low-voltage installations.

IEC 62066 is a technical report that presents a general overview on the different kinds of surge overvoltages that can occur on low-voltage installations. Typical surge magnitude and duration as well as frequency of occurrence are described. Information on overvoltages resulting from interactions between power system and communications system is also provided.

Additionally, general guidelines are given concerning surge protection means and systems on the basis of availability and risk considerations, including interactions and the need for coordination and consideration of temporary overvoltages in the selection of surge-protective devices.