BS EN 50588-1:2017

European foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Environmental classes
5 Electrical characteristics
6 Load loss, no load loss, PEI, sound power level,
   short-circuit impedance
7 Tolerances
8 Rating plate
9 Tests
10 Design requirements
11 Accessories
Annex A (informative) - Calculation of PEI and k[PEI]
Annex B (informative) - A-deviations
Annex ZZ (informative) - Relationship between this European
         Standard and eco-design requirements of Commission
         Regulation (EU) No 548/2014 aimed be covered
Bibliography

Defines medium power transformers. 'Medium power transformer' means a power transformer with a highest voltage for equipment higher than 1,1 kV, but not exceeding 36 kV and a rated power equal to or higher than 5 kVA but lower than 40 MVA.

This European Standard covers medium power transformers. ‘ Medium power transformer’ means a power transformer with a highest voltage for equipment higher than 1,1kV, but not exceeding 36kV and a rated power equal to or higher than 5kVA but lower than 40MVA. National practices may require the use of highest voltages for equipment up to (but not including) 52kV, when the rated voltage is less than 36kV (such as U m=38,5kV or U m=40,5kV). This is considered to be an unusual case of a large power transformer, where the requirements are those for a medium power transformer with U m=36kV. NOTE1 ‘Large power transformer’ means a power transformer with a highest voltage for equipment exceeding 36kV and a rated power equal to or higher than 5kVA, or a rated power equal to or higher than 40MVA regardless of the highest voltage for equipment. Large power transformers are in the scope of EN50629 . NOTE2 Transformers with tap changer (DETC or OLTC) are included in this European Standard even if they have separate tapping winding. The object of this European Standard is to set up requirements related to electrical characteristics and design of medium power transformers. The following transformers are excluded from this European Standard: instrument transformers, specifically designed to supply measuring instruments, meters, relays and other similar apparatus; transformers with low-voltage windings specifically designed for use with rectifiers to provide a DC supply; transformers specifically designed to be directly connected to a furnace; transformers specifically designed for offshore applications and floating offshore applications; transformers specially designed for emergency installations; transformers and auto-transformers specifically designed for railway feeding systems; earthing or grounding transformers, this is, three-phase transformers intended to provide a neutral point for system grounding purposes; traction transformers mounted on rolling stock, this is, transformers connected to an AC or DC contact line, directly or through a converter, used in fixed installations of railway applications; starting transformers, specifically designed for starting three-phase induction motors so as to eliminate supply voltage dips; testing transformers, specifically designed to be used in a circuit to produce a specific voltage or current for the purpose of testing electrical equipment; welding transformers, specifically designed for use in arc welding equipment or resistance welding equipment; transformers specifically designed for explosion-proof and underground mining applications; transformers specifically designed for deep water (submerged) applications; medium Voltage (MV) to Medium Voltage (MV) interface transformers up to 5 MVA; large power transformers where it is demonstrated that for a particular application, technically feasible alternatives are not available to meet the minimum efficiency requirements set out by the commission regulation (EU) No 548/2014; large power transformers which are like for like replacements in the same physical location/installation for existing large power transformers, where this replacement cannot be achieved without entailing disproportionate costs associated to their transportation and/or installation. In case one of the last two exclusions is claimed, this should be documented at the signature of the contract with a declaration made by the customer. NOTE3 This standard covers the transformers under the Commission Regulation (EU) No. 548/2014 and gives additional specific guidance for single phase transformers, multi winding transformers and for transformers with OF or OD cooling systems, necessary for the correct application of energy efficiency requirements to these categories of transformers.