AS 1243-1982

1 - AS 1243-1982 VOLTAGE TRANSFORMERS FOR MEASUREMENT AND PROTECTION
4 - PREFACE
6 - CONTENTS
7 - SECTION 1. SCOPE AND GENERAL REQUIREMENTS
7 - 1.1 SCOPE.
7 - 1.2 APPLICATION.
7 - 1.3 DEFINITIONS.
7 - 1.3.1 General.
7 - 1.3.2 Definitions Relating to Construction.
8 - 1.3.3 Definitions Relating to Performance.
8 - 1.3.4 Definitions Relating to Service Conditions of a Three- phase System.
9 - 1.3.5 Definitions Relating to Capacitor Voltage Transformers (CVTs)
9 - 1.3.6 Definitions Relating to Residual Voltage.
10 - 1.4 SERVICE CONDITIONS
10 - 1.5 RATED FREQUENCY.
10 - 1.6 RATED INSULATION LEVEL (RIL)
10 - 1.6.1 Selection.
10 - 1.6.2 Method of Expression.
10 - 1.7 RATED PRIMARY VOLTAGE.
12 - 1.8 OVERVOLTAGE RATINGS.
12 - 1.9 ACCURACY.
12 - 1.9.1 Classification System.
12 - 1.9.2 Conditions for Compliance With Error Limits.
12 - 1.9.3 VT With More Than One Secondary Winding.
12 - 1.9.4 VT Having a Secondary Winding With Two Classifications.
13 - 1.10 TEMPERATURE RISE.
13 - 1.10.1 General.
13 - 1.10.2 Temperature Rise of Windings.
13 - 1.10.3 Temperature Rise of Oil.
13 - 1.10.4 Temperature Rise of Core or Other Metallic Parts.
13 - 1.11 CURRENT DENSITY.
13 - 1.12 SECONDARY WINDINGS.
13 - 1.13 MARKINGS.
14 - 1.14 ROUTINE TESTS.
14 - 1.14.1 General.
14 - 1.14.2 Verification of Terminal Markings.
14 - 1.14.3 Short Duration Power-frequency Withstand Tests on Secondary Installation.
15 - 1.14.4 Short Duration Power-frequency Withstand Tests (dry) on Primary Insulation.
15 - 1.14.5 Partial Discharge Test.
15 - 1.14.6 Routine Tests for Accuracy
16 - 1.14.7 Measurement of Dielectric Dissipation Factor (Tangent Delta)
16 - 1.15 TYPE TESTS.
16 - 1.15.1 General.
16 - 1.15.2 Power-frequency Withstand Test (Wet) on Outdoor VTs.
16 - 1.15.3 Impulse-voltage Withstand Test on Primary Insulation.
17 - 1.15.4 Tests for Temperature Rise.
17 - 1.15.5 Tests for Current Density in Windings.
18 - 1.15.6 Type Tests for Accuracy.
18 - 1.16 SPECIAL TYPE TEST-RADIO INFLUENCE VOLTAGE (RIV) TEST.
18 - 1.17 COMMISSIONING TESTS.
19 - SECTION 2. SINGLE-PHASE ELECTROMAGNETIC VOLTAGE TRANSFORMERS
19 - 2.1 SCOPE OF SECTION.
19 - 2.2 APPLICATION.
19 - 2.3 RATED SECONDARY VOLTAGE.
19 - 2.4 RATED BURDEN AND OUTPUT.
19 - 2.5 RATED VOLTAGE FACTOR AND RATED DURATION.
19 - 2.6 TERMINAL MARKINGS.
19 - 2.6.1 Marking.
19 - 2.6.2 System of Identification.
19 - 2.6.3 Polarity of Windings.
19 - 2.7 TYPE TESTING FOR ACCURACY OF SINGLE- PHASE UNIFORMLY INSULATED VTs.
19 - 2.7.1 Tests for Symmetry of Primary Winding.
20 - 2.7.2 Further Tests for Accuracy.
21 - SECTION 3. CAPACITOR VOLTAGE TRANSFORMERS
21 - 3.1 SCOPE OF SECTION.
21 - 3.2 APPLICATION.
21 - 3.3 RATED SECONDARY VOLTAGE.
21 - 3.4 RATED BURDEN AND OUTPUT.
21 - 3.5 RATED VOLTAGE FACTOR AND RATED DURATION.
21 - 3.6 SPECIAL REQUIREMENTS.
21 - 3.6.1 Capacitor Voltage Divider (CVD).
21 - 3.6.2 Carrier-frequency Coupling.
21 - 3.7 CONDITIONS FOR COMPLIANCE WITH ERROR LIMITS.
21 - 3.8 TERMINAL MARKINGS.
21 - 3.8.1 General.
21 - 3.8.2 System of Identification.
21 - 3.8.3 Polarity of Windings.
22 - 3.9 MARKINGS.
22 - 3.10 TRANSIENT RESPONSE TO PRIMARY SHORT CIRCUIT.
22 - 3.11 FERRO-RESONANCE.
22 - 3.11.1 With Zero Burden.
22 - 3.11.2 With 0.25 p.u. Rated Burden.
22 - 3.12 OVERVOLTAGE PROTECTIVE DEVICE.
22 - 3.13 ROUTINE TESTS.
22 - 3.13.1 Variation of Section 1 Requirements.
23 - 3.13.2 Additional Tests.
23 - 3.14 TYPE TESTS.
23 - 3.14.1 Variation of Section 1 Requirements.
23 - 3.14.2 Additional Tests.
23 - 3.15 COMMISSIONING TEST.
24 - SECTION 4. THREE-PHASE VOLTAGE TRANSFORMERS
24 - 4.1 SCOPE OF SECTION.
24 - 4.2 APPLICATION.
24 - 4.3 CATEGORY OF PERFORMANCE.
24 - 4.4 RATED VOLTAGES.
24 - 4.5 RATED BURDEN AND OUTPUT.
24 - 4.5.1 For VTs Other Than Designation R.
24 - 4.5.2 For Designation R VTs.
24 - 4.6 RATED VOLTAGE FACTOR AND RATED DURATION.
24 - 4.6.1 For VTs Other Than Designation R.
24 - 4.6.2 For Designation R VTs.
24 - 4.7 ACCURACY.
24 - 4.7.1 Accuracy of Three-phase Category A VTs.
24 - 4.7.2 Accuracy of Three-phase Category B VTs.
26 - 4.7.3 Accuracy of Designation R VTs.
26 - 4.8 TERMINAL MARKINGS.
26 - 4.8.1 General.
26 - 4.8.2 System of Identification.
26 - 4.8.3 Polarity of Windings.
26 - 4.9 TERMINALPOSITIONS.
26 - 4.10 ROUTINE TESTS.
26 - 4.10.1 Variation of Section 1 Requirements.
26 - 4.10.2 Power-frequency Withstand Tests on Non-uniformly Insulated VTs.
26 - 4.10.3 Tests for Accuracy.
28 - 4.10.4 Symmetrical Voltage Tests on Designation R VT.
28 - 4.11 TYPE TESTS.
28 - 4.11.1 Variation of Section 1 Requirements.
28 - 4.11.2 Unsymmetrical Tests on Three- phase Category B VTs and Designation R VTs Having Two Secondary Windings.
30 - SECTION 5. DESIGNATION L VOLTAGE TRANSFORMERS
30 - 5.1 SCOPE OF SECTION.
30 - 5.2 APPLICATION.
30 - 5.3 RATED PRIMARY VOLTAGE.
30 - 5.4 RATED SECONDARY VOLTAGES.
30 - 5.5 RATED BURDEN.
30 - 5.6 RATED VOLTAGE FACTOR AND RATED DURATION.
30 - 5.7 ACCURACY.
30 - 5.8 TERMINAL MARKINGS.
30 - 5.8.1 System of Identification.
30 - 5.8.2 Polarity of Windings.
30 - 5.8.3 Marking.
30 - 5.9 ACCURACY TESTING OF UNIFORMLY INSULATED DESIGNATION L VTs.
30 - 5.9.1 Tests for Symmetry of Primary Winding.
31 - 5.9.2 Further Tests for Accuracy.
32 - APPENDIX A - SERVICE CONDITIONS
32 - A1 AMBIENT TEMPERATURE.
32 - A2 LOCAL ATMOSPHERIC AND CLIMATIC CONDITIONS.
33 - APPENDIX B - GUIDANCE IN THE SELECTION OF RATED VOLTAGE FACTOR
34 - APPENDIX C - CLASSES OF ACCURACY AND THEIR APPLICATIONS
36 - APPENDIX D - DERIVATION OF ERRORS AT DIFFERING BURDENS AND POWER FACTORS
36 - D1 THEORY.
36 - D2 CONSTRUCTION OF THE DIAGRAM.
37 - D3 ANALYTICAL METHOD.
37 - D4 EXAMPLE OF CALCULATION.
39 - APPENDIX E - TEMPERATURE MEASUREMENTS
39 - E1 INTRODUCTION.
39 - E2 MEASUREMENT OF TEMPERATURE RISE OF WINDINGS
39 - E3 MEASUREMENT OF TEMPERATURE OF OIL
39 - E4 MEASUREMENT OF TEMPERATURE OF CORES OR OTHER METALLIC PARTS FOR DESIGNS NOT UTILIZING LIQUID INSULANT.
39 - E5 DURATION OF THE TEMPERATURE-RISE TESTS.
40 - E6 ERRORS IN TEMPERATURE-RISE TESTS.
41 - APPENDIX F - DETECTION OF INSULATION FAILURE DURING AN IMPULSE VOLTAGE WITHSTAND TEST
42 - APPENDIX G - DETERMINATION OF PRIMARY AND SECONDARY CURRENTS
42 - G1 APPLICATION.
42 - G2 METHOD 1: ENERGIZATION OF THE PRIMARY WINDING.
42 - G2.1 For Single-phase VTs having 1.5 or 1.9, and for Three phase Category A VTs having Fv = 1.5.
43 - G2.2 For Three-phase Category B VTs.
44 - G3 METHOD 2: ENERGIZATION OF THE SECONDARY WINDING.
44 - G3.1 For Single-phase VTs having Fv = 1.5 or 1.9, and for Three-phase Category A VTs having Fv = 1.5.
45 - G3.2 For Three phase Category B VTs.
46 - APPENDIX H - DETERMINATION OF TEMPERATURE COEFFICIENTS OF ERROR
46 - H1 TEMPERATURE COEFFICIENTS OF ERROR.
46 - H2 METHODS OF DETERMINATION OF COEFFICIENTS.
46 - H3 DETERMINATION BY MEASUREMENT.
46 - H4 DETERMINATION BY CALCULATION FOR ELECTROMAGNETIC VTs.
47 - APPENDIX J - METHOD OF TEST FOR RADIO INFLUENCE VOLTAGE (RIV)
47 - J1 ARRANGEMENT.
47 - J2 TEST EQUIPMENT.
47 - J3 TEST PROCEDURE.
49 - APPENDIX K - RESIDUAL VOLTAGE WINDINGS
51 - APPENDIX L - ACCURACY TESTS ON THREE-PHASE VTs (including three-phase groups of single-phase VTs)
51 - L1 CATEGORY A PERFORMANCE VTs.
51 - L2 CATEGORY B PERFORMANCE VTs.
52 - L3 VTs WITH RESIDUALLY-CONNECTED SECONDARY WINDINGS.
57 - APPENDIX M - SYSTEM VOLTAGES UNDER UNSYMMETRICAL CONDITIONS
59 - APPENDIX N - INFORMATION TO BE SUPPLIED WITH ENQUIRY AND ORDER
60 - APPENDIX O - ALPHABETICAL INDEX OF DEFINED TERMS

Specifies general requirements and tests for all types of VTs and, in separate sections, specific requirements for single-phase VTs, for CVTs, for three-phase VTs and for Designation L VTs. Deals specifically with accuracy and short-term and long-term overvoltage ratings and applies the rated voltage factor to the VT as an entity, as well as to individual secondary windings. Primary windings are classified as 'uniformly insulated' or 'non-uniformly insulated'. Categories of performance (A and B) are specified for three-phase VTs only. Includes many explanatory appendices and enlarges on the determination of primary and secondary currents and of temperature coefficients of error, and on the determination of errors under different conditions.

This standard specifies requirements for voltage transformers for use with electrical measuring instruments and electrical protection devices such as are covered, in general, by the following Australian standards: AS 1284 Electricity Meters AS 1024 Direct Recording Electrical Measuring Instruments and Their Accessories AS 1042 Direct-acting Indicating Electrical Measuring Instruments and Their Accessories AS 1384 Transducers for Electrical Measurements AS 2481 All-or-nothing Electrical Relays.NOTES:1. Throughout this standard, the words 'voltage transformer' are abbreviated to VT and 'capacitor voltage transformer' to CVT. (The plurals are VTs and CVTs respectively.)2. In order to facilitate the specification and purchase of VTs, the standard also lists information which should be supplied with enquiry and order (see Appendix N).3. Particular attention is drawn to the Foreword to AS 1384 concerning possible peculiarities in the burdens imposed on VTs by certain transducers.

Under Revision see DR 03344 CP. Under Revision see DR 03345 CP