BS EN 61558-2-15:2001

Safety of power transformers, power supply units and similar. Particular requirements for isolating transformers for the supply of medical locations | Status: Revised, Withdrawn

1 Scope Replacement: This international standard deals with all aspects of safety such as electrical, thermal and mechanical. This part 2-15 of EN 61558 applies to stationary, single-phase or polyphase, air-cooled (natural or forced) isolating transformers for the supply of group II medical locations, designed to be permanently connected to the fixed wiring and intended to form the IT system on the secondary side, having a rated supply voltage not exceeding AC 1 kV and rated frequency not exceeding 500 Hz. The rated output shall not be less than 0,5 kVA and shall not exceed 10 kVA.

NOTE 1 — Details of IT supply systems are to be found in IEC 60364-3.

NOTE 2 — The wiring rules for group II medical locations are under consideration [1]* .

The no-load output voltage and the rated output voltage shall not exceed 250 V a.c. single-phase or polyphase (phase-to-phase voltage). Isolating transformers are used where double or reinforced insulation between circuits is required by the installation rules or by the appliance specification. This standard is applicable to dry-type transformers. The winding may be encapsulated or non-encapsulated.

NOTE 3 — For transformers filled with liquid dielectric or pulverised material such as sand, requirements are under consideration.

NOTE 4 — Attention is drawn to the fact that:

• — for transformers intended to be used in tropical countries, special requirements may be necessary;
• — in locations where special environmental conditions prevail, particular requirements may be necessary.

This standard also applies to transformers incorporating electronic circuits. This standard does not apply to external circuits and their components intended to be connected to the input and output terminals or socket-outlets of the transformer.

NOTE Z1 Transformers for medical appliance are not covered by this standard.