scope:

This part of IEC 61558 deals with safety aspects of isolating transformers for the supply of medical locations.

NOTE 1 Safety includes electrical, thermal and mechanical aspects.

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 non-encapsulated.

NOTE 2 IT power systems are defined in IEC 60364-1.

NOTE 3 The installation rules for medical IT systems for group 2 medical locations are covered by IEC 60364-7-710.

NOTE 4 Transformers covered by this standard are intended for the supply of medical locations. All other transformers or equipments connected downstream from the transformer are not covered by this Part 2.

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 singlephase 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.

NOTE 5 Transformers intended to supply power to distribution networks are not covered by this standard.

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.

NOTE 6 Attention is drawn to the following:

- for transformers intended to be used in vehicles, on board ships, and aircraft, additional requirements (from other applicable standards, national rules, etc.) may be necessary;

- measures to protect the enclosure and the components inside the enclosure against external influences such as fungus, vermin, termites, solar-radiation, and icing should also be considered;

- the different conditions for transportation, storage, and operation of the transformers should also be considered;

- additional requirements in accordance with other appropriate standards and national rules may be applicable to transformers intended for use in special environments.