This part of GB 1094 applies to dry-type power transformers (including auto-transformers) having values of highest voltage for equipment up to and including 40.5 kV and at least one winding operating at greater than 1.1 kV. The standard applies to all construction technologies.
This standard does not apply to:
——gas-filled dry type transformers where the gas is not air;
——single-phase transformers rated at less than 5 kVA;
——poly-phase transformers rated at less than 15 kVA;
——instrument transformers;
——starting transformers;
——testing transformers;
——traction transformers mounted on rolling stock;
——flameproof and mining transformers;
——welding transformers;
——voltage regulating transformers;
——small power transformers in which safety is a special consideration.
Where corresponding standards do not exist for the transformers mentioned above or for other special transformers, this part may be applicable as a whole or in parts.
2 Normative References
The following standards contain provisions which, through reference in this part of GB 1094, constitute provisions of this part. For dated references, subsequent amendments to (excluding corrections to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the referenced document applies.
GB 311.1 Insulation Co-ordination for High Voltage Transmission and Distribution Equipment (GB 311.1-1997, neq IEC 60071-1:1993)
GB 1094.1 Power Transformers—Part 1: General (GB 1094.1-1996, eqv IEC 60076-1:1993)
GB 1094.2 Power Transformers—Part 2: Temperature Rise (GB 1094.2-1996, eqv IEC 60076-2:1993)
GB 1094.3 Power Transformers—Part 3: Insulation Levels, Dielectric Tests and External Clearances in Air (GB 1094.3-2003, IEC 60076-3:2000, MOD)
GB 1094.5 Power Transformers—Part 5: Ability to Withstand Short Circuit (GB 1094.5-2003, IEC 60076-5:2000, MOD)
GB/T 1094.10 Power Transformers—Part 10: Determination of Sound Levels (GB/T 1094.10-2003, IEC 60076-10:2001, MOD)
GB/T 2900.15 Electrotechnical Terminology—Transformer, Instrument Transformer, Voltage Regulator and Reactor (GB/T 2900.15-1997, neq IEC 60050-421:1990, IEC 60050-321:1986)
GB 4208 Degrees of Protection Provided by Enclosures (IP Code) (GB 4208-1993, eqv IEC 60529:1989)
GB/T 18380.3 Tests on Electric Cables under Fire Conditions—Part 3: Tests on Bunched Wires or Cables (GB/T 18380.3-2001, idt IEC 60332-3:1992)
3 Terms and Definitions
For the purposes of this part, the terms and definitions given in GB/T 2900.15 and the followings apply.
3.1
dry-type transformer
transformer of which the iron core and windings are not immersed in an insulating liquid
3.2
totally enclosed dry-type transformer
transformer in an un-pressurized enclosure cooled by the circulation of the internal air
3.3
enclosed dry-type transformer
transformer in a ventilated enclosure cooled by the circulation of the external air
3.4
non-enclosed dry-type transformer
transformer supplied without a protective enclosure cooled by natural or forced air ventilation
Foreword i 1 Scope 2 Normative References 3 Terms and Definitions 4 Service Conditions 4.1 General 4.2 Normal Service Conditions 4.3 Electromagnetic Compatibility (EMC) 4.4 Provision for Unusual Service Conditions 4.5 Transport and Storage Conditions 5 Tappings 6 Connections 7 Ability to Withstand Short Circuit 8 Rating 8.1 General 8.2 Rated Power 8.3 Preferred Values of Rated Power 8.4 Operation at Higher Than Rated Voltage 8.5 Operation with Fan Cooling 8.6 Operation in an Enclosure 9 Rating Plate 9.1 Rating Plate Fitted to the Transformer 9.2 Rating Plate Fitted to the Transformer Enclosure 10 Identification according to Cooling Method 10.1 Identification Symbols 10.2 Arrangement of Symbols 11 Temperature-rise Limits 11.1 Normal Temperature-rise Limits 11.2 Reduced Temperature Rises for Transformers Designed for High Cooling Air Temperatures or Special Air Cooling Conditions 11.3 High Altitude Temperature Rise Correction 12 Insulation Levels 12.1 General 12.2 Transformers for Use at High Altitudes 13 Climatic, Environmental and Fire Behaviour Classes 13.1 Climatic Classes 13.2 Environmental Classes 13.3 Fire Behaviour Classes 13.4 Test Criteria for Climatic, Environmental and Fire Behaviour Classes 14 General Requirements for Tests 15 Measurement of Winding Resistance (Routine Test) 16 Measurement of Voltage Ratio and Check of Phase Displacement (Routine Test) 17 Measurement of Short-Circuit Impedance and Load Loss (Routine Test) 18 Measurement of No-load Loss and Current (Routine Test) 19 Separate-Source AC Withstand Voltage Test (Routine Test) 20 Induced AC Withstand Voltage Test (Routine Test) 21 Lightning Impulse Test (Type Test) 22 Partial Discharge Measurement (Routine and Special Test) 22.1 General 22.2 Basic Measuring Circuit (Typical Only) 22.3 Calibration of the Measuring Circuit 22.4 Voltage Application 22.5 Partial Discharge Acceptance Levels 23 Temperature-Rise Test (Type Test) 23.1 General 23.2 Methods of Loading 23.3 Winding Temperature-Rise Correction for Reduced Current 23.4 Determination of Steady State Conditions 24 Measurement of Sound Level (Special Test) 25 Short-Circuit Test (Special Test) 26 Environmental Test (Special Test) 26.1 General 26.2 Validity of the Test 26.3 Testing Procedure 27 Climatic Test (Special Test) 27.1 General 27.2 Validity of the Test 27.3 Climatic test (Thermal Shock Test) for C1 Class Transformers 27.4 Climatic Test (Thermal Shock Test) for C2 Class Transformers 28 Fire Behaviour Test (Special Test) 28.1 General 28.2 Checking of Corrosive and Harmful Gases Emission 28.3 Fire Behaviour Test for F1 Class Transformer 28.4 Quantities to be Measured and Measuring Devices 28.5 Calibration of the Test Chamber without Test Object 28.6 Test Method 28.7 Test Report 28.8 Criteria for Evaluating the Test Results 29 Tolerances 30 Protection against Direct Contact 31 Degrees of Protection Provided by Enclosures 32 Earthing Terminal 33 Information Required with Enquiry and Order 34 Information Concerning Installation and Safety Annex A (Informative) Corresponding Numbering Equivalent Clauses and Tables between this Part and IEC 60076-11:2004 Annex B (Informative) Technical differences and their Causes between this Part and IEC 60076-11:2004 Annex C (Informative) Insulation Levels Based on North American Practice in IEC 60076-11:2004 Annex D (Informative) Installation and Safety of Dry-Type Transformers
