scope:

Replacement:
This part of IEC 61558 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.
This Part 2-16 applies to:
A) Switch mode power supply units incorporating safety isolating transformers providing SELV, PELV or FELV a.c. or d.c. 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 60065, IEC 61347 series, IEC 61204 and IEC 60950.
B) Switch mode power supply units with a maximum output voltage not exceeding 1 000 V a.c. or 1 414 V ripple free d.c. for use with household and other consumer products, except for products covered in A) and products covered by IEC 60065, IEC 61347 series, IEC 61204 and IEC 60950.
C) This standard may be used for transformers for use in switch mode power supply units (see Annex 2).
This standard shall be used in conjunction with all parts 2 of IEC 61558, the series of transformers for safety of transformers, reactors, power supply units, and similar products.
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 1 100 V a.c., 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 on-encapsulated windings.
Associated transformers for switch mode power supply units covered by Annex 2 of this standard, shall have a rated output not exceeding:
- 25 kVA for single-phase transformers
- 40 kVA for polyphase transformers
NOTE2 For higher frequencies, additional requirements may be necessary. However this standard may be used as a guide
The no-load output voltage or the rated output voltage of switch mode power supply units shall not exceed:
- 1 000 V a.c. or 1 415 V ripple free d.c. when separating transformers or auto-transformers are used
- 500 V a.c. or 708 V ripple free d.c. when isolating transformers are used
- 50 V a.c. or 120 V ripple free d.c. when safety isolating transformers are used
The no-load output voltage or the rated output voltage of independent switch mode power supply units shall not be less than:
- 50 V a.c. or 120 V ripple free d.c. when separating transformers or
autotransformers are used.
This standard is also applicable to switch mode power supply units, converters and inverters
without limitation of the rated output. However, such switch mode power supply units are for special applications and are subject to an agreement between the purchaser and the manufacturer.
NOTE 3 - In the context of this standard, converters and invertors are considered switch mode power supply units.
This standard may also be used as a guide for products not covered by the scope of this standard, the scope of IEC 61204, or the scope of IEC 61347.
This standard does not apply to:
- motor-generator sets;
- uninterruptible power supplies (UPS) according to IEC 62040;
- switch mode power supply units covered by IEC 61204 (i.e., Low-Voltage power supply devices, d.c. output - Performance characteristics) and DC power and distribution equipment and switch mode power supply units for use in applications covered by IEC 60950, IEC 61010-1, IEC 60601-1, and IEC 60065.
- lamp control gear covered by IEC 61347-1.
- to external circuits and their components intended to be connected to the input terminals and output terminals of the transformers
NOTE 4 IEC 61204 will be updated by SC 22E
NOTE 5 Attention is drawn to the following:
- for transformers 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 transformers should also be
considered;
- additional requirements in accordance with other appropriate standards and national rules may be applicable to transformers intended for use in special environments, such as tropical environment.
NOTE 6 Future technological development of transformers may necessitate a need to increase the upper limit of the frequencies, until then this Part 2-16 may be used as a guidance document.
Unless otherwise specified, from here onward, the term SMPS covers switch mode power supply
units.