This part of International Standard IEC 60076 applies to three-phase and single-phase power transformers (including auto-transformers) with the exception of certain categories of small and special transformers such as:
– single-phase transformers with rated power less than 1 kVA and three-phase transformers less than 5 kVA;
– instrument transformers;
– transformers for static convertors;
– traction transformers mounted on rolling stock;
– starting transformers;
– testing transformers;
– welding transformers.
When IEC standards do not exist for such categories of transformers, this part of IEC 60076 may still be applicable either as a whole or in part.
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.*
At several places in this part it is specified or recommended that an 'agreement' shall be reached concerning alternative or additional technical solutions or procedures. Such agreement is to be made between the manufacturer and the purchaser. The matters should preferably be raised at an early stage and the agreements included in the contract specification.
* Such standards exist for dry-type transformers (IEC 60726), for reactors in general (IEC 60289), for traction transformers and reactors (IEC 60310), and are under preparation for static convertor transformers.