Safety of Power Transformers, Power Supply Units and Similar - Part 2: Particular Requirements for Separating Transformers for General Use

This part 2 of IEC 61558 applies to stationary or portable, single-phase or polyphase, aircooled separating transformers, associated or not, having a rated supply voltage not exceeding 1000 V a.c., a rated frequency not exceeding 500 Hz, and a rated output not exceeding: . 1 kVA for single-phase transformers; . 5 kVA for polyphase transformers.

This standard is also applicable to separating transformers having a rating up to 40 kVA, however such transformers are considered as special transformers and are subjected to an agreement between the purchaser and the supplier.

The no-load output voltage or the rated output voltage shall not exceed 1000 V a.c. or 1415 V ripple-free d.c.

This standard applies to transformers where double or reinforced insulation between circuits is not required by the installation rules or by the appliance specification.

NOTE 1 . Normally, the transformers are intended to be associated with equipment to provide voltages different from the supply voltage for the functional requirement of the equipment. The safety insulation may be provided (or completed) by other features of the equipment, such as the body. Parts of output circuits may be connected to the input circuit or to protective earth.

This standard is also applicable to transformers associated with specific items of equipment, to the extent decided upon by the relevant IEC technical committees.

This standard is applicable to dry type transformers. The windings may be encapsulated or non-encapsulated.