SURGE OVERVOLTAGES AND SURGE PROTECTION IN LOW-VOLTAGE A.C. POWER SYSTEMS - GENERAL BASIC INFORMATION
International Electrotechnical Committee
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
Gives 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.
| Document Type | Standard |
| Status | Current |
| Publisher | International Electrotechnical Committee |
| Committee | TC 64 |
