NECA 409-2015

This standard describes the installation and maintenance procedures for single- and threephase general purpose dry-type transformers and associated accessories rated 1000 Volts AC or less, and 0.25 kVA or more. This publication applies to indoor and outdoor, ventilated and non-ventilated, two-winding transformers used for supplying power, heating, and lighting loads for commercial, institutional, and industrial use in nonhazardous locations both indoors and outdoors.

It also covers periodic routine maintenance and troubleshooting procedures for transformers, and special procedures used after adverse operating conditions such as a short-circuit, ground-fault, or immersion in water.