This part of IEC 61558 deals with safety aspects of isolating transformers for the supply of
medical locations.
Unless otherwise specified, from here onward, the term transformer covers isolating
transformers for the supply of medical locations.
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 nonencapsulated.
The rated supply voltage does not exceed 1 000 V a.c. The rated supply frequency and
internal operational frequency do not exceed 500 Hz.
The rated output does not be less than 0,5 kVA and does not exceed 10 kVA for single-phase
and three-phase transformers.
This part is applicable to transformers without limitation of the rated output subject to an
agreement between the purchaser and the manufacturer.
The no-load output voltage and the rated output voltage does not exceed 250 V a.c. for
single-phase or three-phase transformer (phase-to-phase voltage).
This standard do not cover power supply unit.
This part is not applicable to external circuits and their components intended to be connected
to the input terminals and output terminals of the transformers. Transformers covered by this
part are used in applications where double or reinforced insulation between circuits is
required by the installation rules or by the appliance specification.