IEC 60044-7:1999

FOREWORD
1 General
    1.1 Scope
    1.2 Normative references
    1.3 General block diagram of electronic
          voltage transformers
2 Definitions
    2.1 General definitions
    2.2 Additional definitions for single-phase
          electronic protective voltage transformers
    2.3 Index of symbols
3 General requirements
    3.1 General
    3.2 Information to be given for enquiries, tenders
          and orders
4 Normal and special service conditions
    4.1 Normal service conditions
    4.2 Special service conditions
    4.3 Earthing system
5 Ratings
    5.1 Standard values of rated voltages
    5.2 Standard values of rated output
    5.3 Standard values of rated voltage factor
    5.4 Standard values of rated auxiliary power
          supply voltage
    5.5 Standard reference values of other influencing
          parameters
6 Design requirements
    6.1 Insulation requirements for primary voltage
          sensor
    6.2 Insulation requirements for low-voltage
          components
    6.3 Short-circuit withstand capability
    6.4 Limits of temperature rise
    6.5 Radio interference voltage requirements
    6.6 Transmitted overvoltage requirements
    6.7 Electromagnetic compatibility requirements
    6.8 Reliability
    6.9 Abnormal conditions withstand capability
    6.10 Abnormal conditions signalling
    6.11 Mechanical requirements
    6.12 Earthing terminals
7 Classification of tests
    7.1 Type tests
    7.2 Routine tests
    7.3 Special tests
8 Type tests
    8.1 Impulse test on primary voltage terminals
    8.2 Wet test for outdoor type electronic voltage
          transformers
    8.3 Tests for accuracy
    8.4 Test for abnormal conditions withstand capacity
    8.5 Radio interference voltage test
    8.6 Transmitted overvoltage test
    8.7 Electromagnetic compatibility tests
    8.8 Impulse voltage withstand test for low-voltage
          components
    8.9 Transient performance tests
9 Routine tests
    9.1 Verification of terminal markings
    9.2 Power-frequency withstand tests on primary
          voltage terminals and partial discharge
          measurement
    9.3 Power-frequency voltage withstand test for
          low-voltage components
    9.4 Tests for accuracy
10 Special tests
    10.1 Chopped lightning-impulse test on primary
          voltage terminals
    10.2 Measurement of capacitance and dielectric
          dissipation factor
    10.3 Mechanical strength tests
11 Markings
    11.1 Rating plate markings
    11.2 Terminal markings
12 Accuracy requirements for single-phase electronic
    measuring voltage transformers
    12.1 General requirements
    12.2 Maintenance requirements
    12.3 Accuracy class designation for electronic
          measuring voltage transformers
    12.4 Standard accuracy classes for electronic
          measuring voltage transformers
    12.5 Limits of voltage error and phase displacement
          for electronic measuring voltage transformers
13 Additional requirements for single-phase electronic
    protective voltage transformers
    13.1 General requirements
    13.2 Maintenance requirements
    13.3 Accuracy class designation for electronic
          protective voltage transformers
    13.4 Standard accuracy classes for electronic
          protective voltage transformers
    13.5 Limits of voltage error and phase displacement
          for electronic protective voltage transformers
    13.6 Transient performance requirements
Annex A (normative) Burdens for the transient response
test
Annex B (informative) Technical information for electronic
voltage transformers
Annex C (informative) Bibliography

Applies to newly manufactured electronic voltage transformers with analogue output, for use with electrical measuring instruments and electrical protective devices at frequencies from 15 Hz to 100 Hz. The standard covers optical arrangements with electronic components. Three-phase voltage transformers are not included, but some of the requirements apply.