Co-operating organizations
Foreword
Specification
Section one. General
1 Scope
2 References
3 Definitions
4 Service conditions
Section two. Requirements for all voltage transformers
5 Rated frequency
6 Rated secondary voltages
7 Rated outputs
8 Rated transformation ratios
9 Rated voltage factors
10 Characteristics of voltage transformers with
residual voltage windings
11 Limits of temperature rise
12 Rated insulation levels
13 Creepage distances
14 Accuracy class designations
15 Limits of error
16 Marking
17 Test requirements
18 Tests
Section three. Additional requirements for capacitor
voltage transformers
19 General requirements
20 Additional performance requirements
21 Test requirements
22 Marking
Section four. Requirements for capacitors for use with
capacitor voltage transformers
23 General requirements
24 Test requirements
25 Tests
26 Insulation level
27 Marking
Appendices
A Service conditions
B Guidance on the application of measuring voltage
transformers
C Rating of voltage transformers at frequencies other
than rated frequency
D Temperature measurements
E Guidance for installation and operation of
capacitors
F Information required by the manufacturer
Tables
1 Rated transformation ratios
2 Standard values of rated voltage factors
3 Characteristic of voltage transformers with residual
voltage windings
4 Limits of temperature rise of windings
5a Insulation test levels for rated highest equipment
voltages up to and including 72.5 kV
5b Insulation test levels for rated highest equipment
voltages of 100 kV and above
6 Limits of voltage error and phase displacement for
measuring voltage transformers
7 Limits of voltage error and phase displacement for
protective voltage transformers
8 High voltage winding terminal to be earthed during
impulse voltage tests
9 Applied power frequency test voltages on primary
windings (after erection on site)
10 Applied power frequency test high voltage tests for
durations exceeding one minute (after erection on
site)
11 Selection of class of accuracy of measuring voltage
transformers
Figures
1 Single-phase voltage transformer having one or two
secondary windings without tappings
2 Single-phase voltage transformer having one or two
secondary windings with tappings
3 Single-phase or 3-phase voltage transformer with one
residual voltage winding
4 3-phase voltage transformer with one or two
secondary windings without tappings
5 3-phase voltage transformer with one secondary
winding with tappings
6 Circuit for accuracy test on a transformer having a
rated voltage factor of 1.5
7 Circuit for accuracy test on a transformer having a
rated voltage factor of 1.9
8 Circuit for accuracy test on the residual voltage
winding of a transformer having a rated voltage
factor not exceeding 1.5
9 Circuit for accuracy test on the residual voltage
winding of a transformer having a rated voltage
factor of 1.9
10 Alternative circuit for accuracy test on the
residual voltage winding of a transformer having a
rated voltage factor of 1.9
11 Diagrammatic arrangement of capacitor voltage
transformer