IEC 61558-2-4 pdf download – Safety of transformers, reactors, power supply units and similar products for supply voltages up to 1 100 V – Part 2-4: Particular requirements and tests for isolating transformers and power supply units incorporating isolating transformers
1scope
Replacement:
This part of lEC 61558 deals with the safety of isolating transformers for generalapplications and power supply units incorporating isolating transformers for generalapplications. Transformers incorporating electronic circuits are also covered by thisstandard.
NOTE 1 Safety includes electrical,thermal and mechanical aspects.
Unless otherwise specified，from here onward,the term transformer covers isolatingtransformers for general applications and power supply units incorporating isolatingtransformers for general applications.
NOTE 2 For power supply units (linear) this part is applicable.For switch mode power supply units, IEC 61558-2-16 isapplicable together with this part.
This part is applicable to stationary or portable,single-phase or polyphase，air-cooled(natural or forced) independent or associated dry- type transformers.The windings may beencapsulated or non-encapsulated.
The rated supply voltage does not exceed 1 100 v a.c., and the rated supply frequencyand the internal operating frequencies do not exceed 500 Hz.
The rated output does not exceed:
– 25 kvA for single-phase transformers;- 40 kVA for polyphase transformers.
This part is applicable to transformers without limitation of the rated output subject to anagreement between the purchaser and the manufacturer.
NOTE 3 Transformers intended to supply distribution networks are not included in the scope.
The no-load output voltage or the rated output voltage does exceed 50 V a.c. or 120 vripple-free d.c., and where applicable, does not exceed 500 V a.c. or 708 V ripple-free d.c.
The no-load output voltage and the rated output voltage may be up to 1 000 v a.c.or1415 v ripple-free d.c. for special applications.
This part is not applicable to external circuits and their components intended to be connectedto the input terminals and output terminals of the transformers.
Transformers covered by this part are used in applications where double or reinforcedinsulation between circuits is ‘required by the installation rules or by the end productstandard.
NOTE 4Attention is drawn to the following:
– for transformers intended to be used in vehicles,on board ships,and aircraft, additional requirements (fromother applicable standards, national rules,etc.) may be neces5ary;
measures to protect the enelosure and the components inside the enclosure against external influences suchas fungus,vermin, termites,solar-radiation, and icing should also be considered;
the different conditions for transportation,storage，and operation of the transformers should also beconslidered;
additional requirements in accordance with other appropriate standards and national rules may be applicable totransformers intendad for use in speciall environments.
NOTE 5 Future technological development of transformers may necessitate a need to increase the upper limit ofthe frequencies, until then this part may be used as a guidance document,
2Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 61558-1 :2005,Safety of power transformers,power supplies, reactors and similarproducts – Part 1 : General requirements and tests
3Terms and definitions
This clause of Part 1 is applicable.
4 General requirements
This clause of Part 1 is applicable.
5 General notes on tests
This clause of Part 1 is applicable.
6 Ratings
This clause of Part 1 is applicable.Addition:
6.101 The rated output voltage shall exceed 50 v a.c. or 120 V ripple-free d.c. but notexceed;
-250 v a.c. for single-phase portable transformers;- 400 v a.c. for polyphase portable transformers,and
500 V a.c.or 708 V ripple-free d.c. for other transformers. In this case, the rated outputvoltage may be up to 1 000 v a.c. or 1415 V ripple-free d.c. to be in accordance with thenational wiring rules or for a special purpose. This output voltage limitation apply evenwhen output windings, not intended for interconnection, are connected in series.
6.102 The rated output shall not exceed:
– 25 kVA for single-phase transformers;-40 kVA for polyphase transformers;
IEC 61558-2-4 pdf download – Safety of transformers, reactors, power supply units and similar products for supply voltages up to 1 100 V – Part 2-4: Particular requirements and tests for isolating transformers and power supply units incorporating isolating transformers
