GB 20052-2024 English PDF (GB20052-2024)

This document specifies the minimum allowable values of energy efficiency, the energy efficiency grades and test methods for power transformers. This document is applicable to oil-immersed distribution transformers and dry-type distribution transformers with three-phase 10 kV voltage level, non-excitation voltage regulation, rated frequency of 50 Hz and rated capacity of 30 kVA ~ 2,500 kVA; oil-immersed power transformers with 35 kV ~ 500 kV voltage level, rated frequency of 50 Hz and rated capacity of 3,150 kVA and above; oil-immersed transformers and dry-type transformers with three-phase 6 kV ~ 35 kV voltage level, non-excitation voltage regulation, rated frequency of 50 Hz and rated capacity of 500 kVA and above for photovoltaics, wind power and energy storage on the new energy power generation side; oil-immersed transformers with three-phase 66 kV voltage level, non-excitation voltage regulation, rated frequency of 50 Hz and rated capacity of 3,150 kVA ~ 20,000 kVA for photovoltaics, wind power and energy storage on the new energy power generation side. This document is not applicable to inflatable transformers, tower transformers and engine room transformers.