IEC 60076-1-2011 pdf free download.Power transformers – Part1: General.
When IEC standards do not exist for such categories of transformers (in particular transformer having no winding exceeding 1000 V for industrial applications), this part of IEC 60076 may still be applicable either as a whole or in part.
This standard does not address the requirements that would make a transformer suitable for mounting in a position accessible to the general public.
For those categories of power transformers and reactors which have their own IEC standards, this part is applicable only to the extent in which it is specifically called up by cross-reference in the other standard. Such standards exist for:
— reactors in general (IEC 60076-6);
— dry-type transformers (IEC 60076-11);
— self-protected transformers (I EC 60076-13);
— gas-filled power transformers (IEC 60076-15);
— transformers for wind turbine applications (IEC 60076-16);
— traction transformers and traction reactors (IEC 60310);
— converter transformers for industrial applications (IEC 61378-1);
— converter transformers for HVDC applications (IEC 61378-2).
At several places in this part it is specified or recommended that an ‘agreement’ should be reached concerning alternative or additional technical solutions or procedures. Such agreement is made between the manufacturer and the purchaser. The matters should preferably be raised at an early stage and the agreements inc’uded in the contract specification.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60076-2, Power transformers — Part 2: Temperature rise for liquid-immersed transformers
IEC 60076-3:2000, Power transformers — Part 3: Insulation levels, dielectric tests and external clearances in air
IEC 60076-5:2006, Power transformers — Part 5: Ability to withstand short circuit
IEC 60076-10:2001, Power transformers — Part 10: Determination of sound levels
IEC 60076-11:2004. Power transformers — Part 11: Dry-type transformers
IEC 60137:2008, Insulated bushings for alternating voltages above 1 000 V
IEC 60214-1:2003, Tap-changers — Part 1: Performance requirements and test methods
IEC 60296:2003, Fluids for electrotechnical applications — Unused mineral insulating oils for transformers and switch gear
IEC 60721-3-4:1995, Classification of environmental conditions — Part 3: Classification of groups of environmental parameters and their seventies — Section 4: Stationary use at nonweatherprotected locations
ISO 9001:2008, Quality management systems — Requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE Other terms use the meanings ascribed to Ihem in the International Electrotechnical Vocabulary (1EV).
3.1 General
3.1.1 power transformer
a static piece of apparatus with two or more windings which, by electromagnetic induction. transforms a system of alternating voltage and current into another system of voltage and current usually of different values and at the same frequency for the purpose of transmitting electrical power [IEC 60050-421:1990, 421-01-01, moditied]
3.1.2 auto-transformer a transformer in which at least two windings have a common part [IEC 60050-421:1990, 421-01-11]
4 ServIce conditions
4.1 General
The service conditions set Out in 4.2 represent the normal scope of operation of a transformer specified to this standard. For any unusual service conditions which require special consideration in the design of a transformer see 5.5. Such conditions include high altitude, extreme high or low external cooling medium temperature, tropical humidity, seismic activity. severe contamination, unusual voltage or load current wave shapes, high solar radiation and intermittent loading. They may also concern conditions for shipment, storage and installation. such as weight or space limitations (see Annex A).
Supplementary rules for rating and testing are given in the following publications:
— temperature rise and cooling In high external cooling medium temperature or at high altitude: IEC 60076-2 for liquid-immersed transformers, and IEC 60076-11 for dry-type transformers;
— external insulation at high altitude: IEC 60076-3 for liquid-filled transformers, and IEC 60076-11 for dry-type transformers.
4.2 Normal service conditions
This part of IEC 60076 gives detailed requirements for transformers for use under the following conditions:
a) Altitude
A height above sea-level not exceeding 1 000 m.
b) Temperature of cooling medium
The temperature of cooling air at the inlet to the cooling equipment not exceeding:
40 C at any time;
30 C monthly average of the hottest month:
20 C yearly average.
and not below:
—25 C in the case of outdoor transformers:
—5 C in the case of transformers where both the transformer and cooler are intended for installation indoors.
At any time, monthly average and yearly average are defined in 3.12.
The purchaser may specify a higher minimum temperature of cooling medium in which case the minimum temperature of cooling medium shall be stated on the rating plate.IEC 60076-1 pdf free download.