1 Scope
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 7354 Partial Discharge Measurements (GB/T 7354-2003, IEC 60270:2000, IDT)
GB/T 11021 Thermal Evaluation and Classification of Electrical Insulation (GB/T 11021-1989, eqv IEC 60085:1984)
GB/T 17211-1998 Loading Guide for Dry-type Power Transformers (eqv IEC 60905:1987)
GB/T 17467 High-voltage/Low-voltage Prefabricated Substation (GB/T 17467-1998, eqv IEC 61330:1995)
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
