IEC 60076-1:2011 applies to three-phase and single-phase power transformers (including auto-transformers) with the exception of certain categories of small and special transformers. For those categories of power transformers and reactors which have their own IEC standards, this part is applicable only to the extent in which it is specifically called up by cross-reference in the other standard. This new edition includes the following significant technical additions with respect to the previous one: - definition of harmonic content; - subclause on transport; - functional method of specification; - connection symbols for single phase transformers; - safety and environmental requirements; - requirements for liquid preservation systems; - clause on DC currents; - vacuum, pressure and leak tests on tanks; - facilities for condition monitoring and environmental and safety considerations.