AS 60044.1-2003

1 - AS 60044.1-2003 INSTRUMENT TRANSFORMERS - CURRENT TRANSFORMERS (IEC 60044-1:1996, MOD)
4 - PREFACE
6 - CONTENTS
4 - PREFACE
9 - 1 General
9 - 1.1 Scope
10 - 1.2 Normative references
11 - 2 Definitions
11 - 2.1 General definitions
14 - 2.2 Additional definitions for measuring current transformers
15 - 2.3 Additional definitions for protective current transformers
16 - 3 Normal and special service conditions
16 - 3.1 Normal service conditions
17 - 3.2 Special service conditions
18 - 3.3 System earthing
18 - 4 Ratings
18 - 4.1 Standard values of rated primary currents
18 - 4.2 Standard values of rated secondary currents
18 - 4.3 Rated continuous thermal current
18 - 4.4 Standard values of rated output
19 - 4.5 Short- time current ratings
19 - 4.6 Limits of temperature rise
20 - 5 Design requirements
20 - 5.1 Insulation requirements
25 - 5.2 Mechanical requirements
26 - 6 Classification of tests
26 - 6.1 Type tests
27 - 6.2 Routine tests
27 - 6.3 Special tests
27 - 7 Type tests
27 - 7.1 Short- time current tests
28 - 7.2 Temperature- rise test
28 - 7.3 Impulse tests on primary winding
30 - 7.4 Wet test for outdoor type transformers
30 - 7.5 Radio interference voltage measurement
31 - 8 Routine tests
31 - 8.1 Verification of terminal markings
31 - 8.2 Power- frequency withstand tests on primary windings and partial discharge measurement
32 - 8.3 Power- frequency withstand tests between sections of primary and secondary windings and on secondary windings
32 - 8.4 Inter- turn overvoltage test
33 - 9 Special tests
33 - 9.1 Chopped impulse test on primary winding
33 - 9.2 Measurement of capacitance and dielectric dissipation factor
34 - 9.3 Mechanical tests
35 - 10 Markings
35 - 10.1 Terminal markings - General rules
36 - 10.2 Rating plate markings
37 - 11 Additional requirements for measuring current transformers
37 - 11.1 Accuracy class designation for measuring current transformers
37 - 11.2 Limits of current error and phase displacement for measuring current transformers
38 - 11.3 Extended current ratings
38 - 11.4 Type tests for accuracy of measuring current transformers
39 - 11.5 Routine tests for accuracy of measuring current transformers
39 - 11.6 Instrument security factor
39 - 11.7 Marking of the rating plate of a measuring current transformer
39 - 12 Additional requirements for protective current transformers
39 - 12.1 Standard accuracy limit factors
40 - 12.2 Accuracy classes for protective current transformer
40 - 12.3 Limits of errors for protective current transformers
40 - 12.4 Type and routine tests for current error and phase displacement of protective current transformers
41 - 12.5 Type tests for composite error
41 - 12.6 Routine tests for composite error
42 - 12.7 Marking of the rating plate of a protective current transformer
45 - 13 Additional requirements for class PR protective current transformers
45 - 13.1 Standard accuracy limit factors
45 - 13.2 Accuracy classes for class PR protective circuit transformers
45 - 13.3 Limits of error for class PR protective current transformers
46 - 13.4 Type and routine tests for current error and phase displacement of class PR protective current transformers
46 - 13.5 Marking of rating plate of class PR current transformers
47 - 14 Additional requirements for class PX protective current transformers
47 - 14.1 Specification of performance for class PX protective current transformers
47 - 14.2 Insulation requirements for class PX protective current transformers
47 - 14.3 Type tests for class PX protective current transformers
48 - 14.4 Routine tests for class PX protective current transformers
48 - 14.5 Marking of rating plate of class PX current transformers
49 - Annex A - Protective current transformers
49 - A.1 Vector diagram
49 - A.2 Turns correction
49 - A.3 The error triangle
50 - A.4 Composite error
50 - A.5 Direct test for composite error
51 - A.6 Alternative method for the direct measurement of composite error
51 - A.7 Use of composite error
53 - Annex B - Multiple chopped impulse test
54 - Annex ZA - Calibration of a CT at a 0.8 power-factor lagging burden

Specifies requirements and tests for current transformers. It modifies, and has been reproduced from, IEC 60044-1:1996 with variations for Australian conditions.

This part of IEC 44 applies to newly manufactured current transformers for use with electrical measuring instruments and electrical protective devices at frequencies from 15 Hz to 100 Hz. Although the requirements relate basically to transformers with separate windings, they are also applicable, where appropriate, to autotransformers. Clause 11 covers the requirements and tests, in addition to those in clauses 3 to 10, that are necessary for current transformers for use with electrical measuring instruments. Clause 12 covers the requirements and tests, in addition to those in clauses 3 to 10, that are necessary for current transformers for use with electrical protective relays, and in particular for forms of protection in which the prime requirement is the maintenance of accuracy up to several times the rated current. For certain protective systems, where the current transformer characteristics are dependant on the overall design of the protective equipment (for example high-speed balanced systems and earth-fault protection in resonant earthed networks), additional requirements are given in clause 13 for class PR transformers and in clause 14 for class PX transformers. Clause 13 covers the requirements and tests in addition to those in clauses 3 to 10 that are necessary for current transformers for use with electrical protective relays, and in particular for forms of protection in which the prime requirement is the absence of remanent flux. Clause 14 covers the requirements and tests in addition to those in clauses 3 to 10 that are necessary for current transformers for use with electrical protective relays, and in particular for forms of protection for which knowledge of the characteristic, secondary winding resistance, secondary burden resistance and turns ratio is sufficient to assess its performance in relation to the protective relay system with which it is to be used. Current transformers intended for both measurement and protection shall comply with all the clauses of this standard.

First published as part of AS C45-1928.
Second edition 1950.
AS C45-1950 revised and redesignated in part as AS C388-1968.
AS C388 revised and redesignated as AS 1675-1974.
Second edition 1986.
AS 1675-1986 revised and rdesignated as AS 60044.1-2003.