DIN 42508-1 PDF

Transformers; three-phase oil immersed type power transformers with off-circuit tap-changer or with on-load tap-changer 12500 to 80000 kVA for 50 Hz and U<(Index)m> up to 123 kV; characteristics
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 05/01/1983