This part of 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; - transformers, which have no windings with rated voltage higher than 1 000 V; - instrument transformers; - traction transformers mounted on rolling stock; - starting transformers; - testing transformers; - welding transformers; - explosion-proof and mining transformers; - transformers for deep water (submerged) applications. 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 (IEC 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 included in the contract specification.