NEMA ST 20-2014 PDF
The reinstated and revised edition of NEMA ST 20-2014 applies to single-phase and polyphase dry-type transformers (including autotransformers and non-current-limiting reactors) for supplying energy to power, heating, and lighting circuits and designed to be installed and used in accordance with the National Electrical Code®. It covers transformers with and/or without accessories having ratings of 1.2 kV class, 0.25 kVA through 4000 kVA.
