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

This document is applicable to stationary, single-phase or three-phase, air-cooled (natural or forced) dry-type isolating transformers for the supply of medical IT system for group 2 medical locations, designed to be permanently connected to the fixed wiring and intended to form the medical IT system on the secondary side. The windings can be encapsulated or nonencapsulated.

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

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

NOTE 3 National installation rules of some countries have different or additional requirements listed in Annex C of IEC 60364-7-710:2021.

Transformers covered by this document are intended for medical IT systems for the supply of medical locations. All other transformers or equipment are not covered by this document.

The rated supply voltage does not exceed 1 000 V AC. The rated supply frequency and internal operational frequency do not exceed 500 Hz.

The rated output is not less than 0,5 kVA and does not exceed 10 kVA for single-phase and three-phase transformers for medical IT system for group 2 medical locations.

This document can be applicable to isolating transformers intended to supply other medical installations that are not group 2 medical locations without limitation of the rated output subject to an agreement between the purchaser and the manufacturer.

NOTE 4 Transformers intended to supply distribution networks other than medical IT systems are not included in the scope.

The no-load output voltage and the rated output voltage does not exceed 250 V AC for single-phase or three-phase transformer (phase-to-phase voltage).

This document does not cover power supply units.

This document 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 document are used in applications where double or reinforced insulation between circuits is required by the installation rules or by the appliance specification.

Attention is drawn to the following, if necessary:
- additional requirements for transformers intended to be used in vehicles, on board ships, and aircraft (from other applicable standards, national rules, etc.);
- measures to protect the enclosure and the components inside the enclosure against external influences such as fungus, vermin, termites, solar-radiation, and icing;
- the different conditions for transportation, storage, and operation of the transformers;
- additional requirements in accordance with other appropriate standards and national rules may be applicable to transformers intended for use in special environments.

This group safety publication focusing on safety guidance is primarily intended to be used as a product safety standard for the products mentioned in the scope, but is also intended to be used by TCs in the preparation of publications for products similar to those mentioned in the scope of this group safety publication, in accordance with the principles laid down in IEC Guide 104 and lSO/lEC Guide 51.

One of the responsibilities of a TC is, wherever applicable, to make use of BSPs and/or GSPs in the preparation of its publications.