IEEE C62.41-1991

Section
1 Scope
2 How to use this document
2.1 General
2.2 Achieving practical surge immunity
2.2.1 Protection desired
2.2.2 Equipment sensitivities
2.2.3 Power environment - surges
2.2.4 Power environment - electrical system
2.2.5 Performance of surge-protective devices
2.2.6 Test environment
2.2.7 Costs
2.3 Document outline
3 Definitions
4 References
5 The origins of surge voltages
5.1 General
5.2 Lightning
5.3 Switching transients
6 Summary of data base
6.1 General
6.2 Notations and definitions
6.3 Site surveys of power quality
6.4 Field experience
6.5 Summary of surge characteristics
6.5.1 Peak amplitude versus rate of occurrence
6.5.2 Duration
6.5.3 Ringing frequency
6.5.4 Voltage rate of change
6.5.5 Energy delivery capability
6.5.6 Effects of location, loads, and mode of coupling
7 Recommended selection of representative surges
7.1 General
7.2 Simplification of the data base
7.3 Rate of occurrence and voltage levels in
        unprotected circuits
7.3.1 General
7.3.2 Rate of occurrence versus voltage level
7.3.3 Exposure levels
7.4 Recommended waveforms
7.4.1 General
7.4.2 Ring wave
7.4.3 High-energy surges
7.4.4 Fast transients
7.5 Amplitude, energy, and source impedance
7.6 Rate of voltage change
7.7 Location categories
8 Recommended planning for surge immunity
8.1 General
8.2 Reconciling equipment susceptibility and
        environment hostility
8.3 Worst-case design and economic trade-off
8.4 Surge effects
8.5 Selection of waveforms
9 Definition of standard sure-testing waveforms
9.1 General
9.1.1 100 kHz ring wave
9.1.2 Combination wave
9.2 Selection of peak values of standard waveforms
9.3 Test conditions
9.3.1 Powered testing
9.3.2 Verification of the test generator
9.3.3 Tolerances on most important parameter
9.3.4 Unpowered testing
9.4 Detailed specifications of waveforms
9.4.1 0.5 microsecond-100 kHz ring wave
9.4.2 1.2/50 - 8/20 microsecond combination wave
9.5 Equations for standard waveforms
10 Definition of additional surge-testing waveforms
10.1 The electrical fast transient (EFT)
10.1.1 Waveform definition
10.1.2 Amplitude
10.1.3 Test procedures
10.2 The 10/1000 microsecond wave
10.2.1 Waveform definition
10.2.2 Amplitude
10.2.3 Test procedure
10.3 The 5 kHz ring wave
10.3.1 Waveform definition
10.3.2 Amplitude
10.3.3 Test procedures
10.4 Equations for additional waveforms
Appendixes
A - Data base
A1 Initial 1980 data base
A2 Additional data
A3 Review of published data
A4 Relative occurrence of different types of
     disturbances
A5 Differences in amplitude
A6 Differences in waveforms
B - Additional information
B1 Amplitudes of strikes
B2 Amplitude spectral density
B3 Changes in the environment
B4 Description versus specification
B5 Differential mode and common mode
B6 EFT test
B7 Energy delivery capability
B8 Expected occurrence of lightning
B9 Failure rate observations
B10 Installation categories
B11 Interface devices
B12 Level versus rate of occurrence
B13 Low-voltage system oscillatory surges during
     lightning
B14 Multiple strokes and total energy
B15 Open-circuit voltages and wiring sparkover
B16 Per-unit
B17 Power system source impedance
B18 Sparkover of clearances
B19 Surge impedance and source impedance
B20 Surge voltage
B21 Switching surges
B22 Timing of surges with respect to power frequency
B23 Utilities interconnections and interactions
B24 VDE 0160 [B94] high-energy test
B25 Worst case
C - Annotated bibliography
C1 Bibliographic information about references
C2 Recorded occurrences and computed simulations
C3 Propagation, attenuation, and mitigation
C4 Reviews and discussions
C5 Measurement techniques and test methods
C6 Related standards
Figures
Fig 1 Simplified relationships between voltage,
        duration, rate of change, and their effects on
        equipment
Fig 2 Relative number of transients as a function of
        amplitude
Fig 3 Comparison of the slopes of the frequency of
        occurrence versus peaks of the surges among six
        site surveys
Fig 4 Amplitude spectral density at four sites
Fig 5 Statistical evaluation of recorded dv/dt data,
        as a function of the maximum transient amplitude
Fig 6 Rate of surge occurrences versus voltage level
        at unprotected locations
Fig 7 Isokeraunic levels for the United States
Fig 8 Isokeraunic levels for the world
Fig 9 Location categories
Fig 10 Concept of surge immunity
Fig 11 100 kHz ring wave
Fig 12 Combination wave, open-circuit voltage
Fig 13 Combination wave, short-circuit current
Fig 14 Features of the nominal 8/20 microsecond
        waveform: front time, virtual origin, and
        duration
Fig 15 Waveform of the EFT pulse
Fig 16 Pattern of the EFT bursts
Fig 17 Waveform for 10/1000 microsecond current surge
Fig 18 Waveform for 5 kHz ring wave
NUMEROUS APPENDIX FIGURES
Appendix Tables
Table A1 Number of houses with repetitive surge
          activity above 1200 V
Table A2 Surge-counter recordings above 1200 V (spring,
          summer, and fall)
Table A3 Capacitor energizing surges
Table B1 Capacitance value specified for the test
          generator, according to the system voltage and
          the equipment class

Gives information on surge voltages in low voltage ac power circuits. Characterises electrical distribution systems in which surges exist, based upon the data that have been recorded in interior locations on single phase and three phase residential, commercial, and industrial power distribution systems.