Replacement This document of the IEC 61558 series deals with the safety of switch mode power supply units and transformers for switch mode power supply units. Transformers incorporating electronic circuits are also covered by this standard. NOTE 1 Safety includes electrical, thermal and mechanical aspects. IEC 61558-2-16 applies to: a) switch mode power supply units incorporating safety isolating transformers providing SELV, PELV or FELV AC or DC output voltage(s), or a combination thereof according to IEC 61140 and IEC 60364-4-41 for use with household and other consumer products, except for products covered by IEC 61347 series, IEC 61204-7, IEC 60065, IEC 60950-1 and IEC 62368 series; b) switch mode power supply units with a maximum output voltage not exceeding 1 000 V AC or 1 415 V ripple-free DC for use with household and other consumer products, except for products covered in a) and products covered by IEC 61347 series, IEC 61204-7, IEC 60065, IEC 60950-1 and IEC 62368 series; c) IEC 61558-2-16 can be used for transformers for use in switch mode power supply units (see Annex BB). IEC 61558-2-16 covers the safety requirements for: " separating SMPS for general use corresponding to IEC 61558-2-1; " isolating SMPS for general use corresponding to IEC 61558-2-4; " safety isolating SMPS for general use corresponding to IEC 61558-2-6; " auto-SMPS for general use corresponding to IEC 61558-2-13. For SMPS for specific applications corresponding to the other documents of the IEC 61558-2 series, the necessary requirements of the relevant documents of the IEC 61558-2 series are applicable. In addition, the requirements listed in IEC 61558-2-16 apply. Where two requirements are in conflict, the most severe take precedence. NOTE 2 As the maximum rated supply voltage of the internal transformer is 1 000 V, the maximum rated supply voltage of the switch mode power supply unit may be lower due to type of rectification. Switch mode power supply units covered by this standard are air cooled (natural or forced) independent, associated, stationary, portable, single-phase, or polyphase, with the rated supply voltage not exceeding 1 000 V AC, the rated supply frequency not exceeding 500 Hz, the rated internal operating frequency exceeding 500 Hz, but not exceeding 100 MHz, and the rated output not exceeding 1 kVA or 1 kW, incorporating dry-type transformers with encapsulated or non-encapsulated windings. NOTE 3 For higher frequencies, additional requirements may be necessary. However, this standard may be used as a guide. IEC 61558-2-16 is applicable to switch mode power supply units, converters and inverters without limitation of the rated output subject to an agreement between the purchaser and the manufacturer. NOTE 5 In the context of this standard, converters and invertors are considered to be switch mode power supply units. The no-load output voltage or the rated output voltage of switch mode power supply units does not not exceed: 1 000 V AC or 1 415 V ripple-free DC when separating transformers or auto216 transformers are used; 500 V AC or 708 V ripple-free DC when isolating transformers are used; 50 V AC or 120 V ripple-free DC when safety isolating transformers are used. The no-load output voltage or the rated output voltage of independent switch mode power supply units does not be less than: 50 V AC or 120 V ripple-free DC when separating transformers, isolating transformer or autotransformers are used. IEC 61558-2-16 may also be used as a guide for products not covered by the scope of this standard, the scope of IEC 61204-7 or the scope of IEC 61347 series. IEC 61558-2-16 does not apply to: motor-generator sets; uninterruptible power supplies (UPS) according to IEC 62040 (Part 1 or series); switch mode power supply units covered by IEC 61204-7 (i.e., low-voltage power supply devices, DC output, performance characteristics) and DC power and distribution equipment and switch mode power supply units for use in applications covered by, IEC 61010-1, and IEC 60601-1 light source control gear covered by IEC 61347 series; external circuits and their components intended to be connected to the input terminals and output terminals of the switch mode power supply units and transformers for switch mode power supply units. NOTE 4 IEC 61204-7 will be updated by SC 22E. Attention is drawn to the following: for switch mode power supply units and transformers for switch mode power supply units 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 switch mode power supply units and transformers for switch mode power supply units should also be considered; additional requirements in accordance with other appropriate standards and national rules may be applicable to switch mode power supply units and transformers for switch mode power supply units intended for use in special environments, such as tropical environment. Future technological development of switch mode power supply units can necessitate a need to increase the upper limit of the frequencies; until then, IEC 61558-2-16 can be used as a guidance document. Unless otherwise specified, from here onward, the term SMPS covers switch mode power supply units.