DS/EN 50588-1:2017

Medium power transformers 50 Hz, with highest voltage for equipment not exceeding 36 kV - Part 1: General requirements

This European Standard covers 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.*National practices may require the use of highest voltages for equipment up to (but not including) 52 kV, when the rated voltage is less than 36 kV (such as Um = 38,5 kV or Um = 40,5 kV). This is considered to be an unusual case of a large power transformer, where the requirements are those for a medium power transformer with Um = 36 kV.*NOTE 1 – ‘Large power transformer’ means a power transformer with a highest voltage for equipment exceeding 36 kV and a rated power equal to or higher than 5 kVA, or a rated power equal to or higher than 40 MVA regardless of the highest voltage for equipment. Large power transformers are in the scope of EN 50629.*NOTE 2 – 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:*a) instrument transformers, specifically designed to supply measuring instruments, meters, relays and other similar apparatus;*b) transformers with low-voltage windings specifically designed for use with rectifiers to provide a DC supply;*c) transformers specifically designed to be directly connected to a furnace;*d) transformers specifically designed for offshore applications and floating offshore applications;*e) transformers specially designed for emergency installations;*f) transformers and auto-transformers specifically designed for railway feeding systems;*g) earthing or grounding transformers, this is, three-phase transformers intended to provide a neutral point for system grounding purposes;*h) traction t ...