scope:

This part of IEC 61558 deals with the safety of transformers, power supply units and switch mode power supply units all for saving energy and other purposes in electrical installations by adjusting the output voltage and/or other electrical characteristics on the output circuits without interruption affected by the transformers, power supply unit and switch mode power supply unit. The saving of energy is obtained by voltage stabilization and/or voltage adjusting of the electrical installation. This standard may also be used for power supply units and switch mode power supply units intended to be used where adjusting of the voltage or other electrical characteristics is required by the final application. This part applies to single-phase or three-phase transformers, power supply units and switch mode power supply units all for saving energy which are air-cooled (natural or forced), independent or incorporated and containing transformers and/or power supply units from the following parts of the IEC 61558 series: Part 2-1: Particular requirements and tests for separating transformers and power supplies incorporating separating transformers for general applications. Part 2-4: Particular requirements and tests for isolating transformers and power supply units incorporating isolating transformers. Part 2-6: Particular requirements and tests for safety isolating transformers and power supply units incorporating safety isolating transformers. Part 2-13: Particular requirements and tests for auto transformers and power supply units incorporating auto transformers. Part 2-14: Particular requirements and tests for variable transformers and power supply units incorporating variable transformers. Part 2-16: Particular requirements and tests for switch mode power supply units and transformers for switch mode power supply units. The rated supply voltage does not exceed 1000 V a.c., and the rated supply frequency does not exceed 500 Hz.