Grid transformers are primarily designed and tested according to IEC 60076 series (IEC markets) or IEEE/ANSI C57 series (North America). Additional standards include ISO quality frameworks, environmental regulations, regional grid codes, and utility-specific specifications for seismic, overload, sound level, efficiency, and monitoring. Compliance ensures interchangeability, safety, dielectric coordination, thermal limits, and performance under short-circuit and transient conditions typical of transmission and distribution systems.