This part of IEC61558 deals with safety aspects of isolating transformers for the supply of medical locations. Safety includes electrical, thermal and mechanical aspects. This part is applicable to stationary, single-phase or three-phase, air-cooled (natural or forced) independent dry-type isolating transformers for the supply of medical IT systems for group 2 medical locations, designed to be permanently connected to the fixed wiring and intended to form the IT power system on the secondary side. The windings may be encapsulated or non-encapsulated.