CSA IEC 61558-2-4:25
1 Scope
Replacement
This part of IEC 61558 deals with the safety of isolating transformers for general applications
and power supply units incorporating isolating transformers for general applications.
Transformers incorporating electronic circuits are also covered by this document.
NOTE 1 Safety includes electrical, thermal and mechanical aspects.
Unless otherwise specified, from here onward, the term transformer covers isolating
transformers for general applications and power supply units incorporating isolating
transformers for general applications.
For power supply units (linear) this document is applicable. For switch mode power supply
units, IEC 61558-2-16 is applicable.
This document is applicable to stationary or portable, single-phase or polyphase, air-cooled
(natural or forced) independent or associated dry- type transformers. The windings can be
encapsulated or non-encapsulated.
The rated supply voltage does not exceed 1 000 V AC and the rated supply frequency and
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 document is applicable to transformers without limitation of the rated output subject to
an agreement between the purchaser and the manufacturer.
NOTE 2 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 AC or 120 V ripplefree
DC, and where applicable, does not exceed 500 V AC or 708 V ripple-free DC.
The no-load output voltage and the rated output voltage may be up to 1 000 V AC or 1 415 V
ripple-free DC for special applications.
This document is not applicable to external circuits and their components intended to be
connected to the input terminals and output terminals of the transformers.
NOTE 3 Transformers covered by this document are used in applications where double or reinforced insulation
between circuits is required by the installation rules or by the end product standard.
Attention is drawn to the following:
• additional requirements for transformers intended to be used in vehicles, on board ships,
and aircraft (from other applicable standards, national rules, etc.);
• measures to protect the enclosure and the components inside the enclosure against
external influences such as fungus, vermin, termites, solar-radiation, and icing;
• the different conditions for transportation, storage, and operation of the transformers;
• additional requirements in accordance with other appropriate standards and national rules
can be applicable to transformers intended for use in special environments.
Future technological development of transformers can necessitate a need to increase the
upper limit of the frequencies. Until then, this document may be used as a guidance document.
This group safety publication focusing on safety guidance is primarily intended to be used as a
product safety standard for the products mentioned in the scope, but is also intended to be used
by TCs in the preparation of publications for products similar to those mentioned in the scope
of this group safety publication, in accordance with the principles laid down in IEC Guide 104
and lSO/lEC Guide 51.
One of the responsibilities of a TC is, wherever applicable, to make use of BSPs and/or GSPs
in the preparation of its publications.
OEN:
CSA
Langue:
English
Code(s) de l'ICS:
29.180
Statut:
Norme
Date de Publication:
1969-12-30
Numéro Standard:
CSA IEC 61558-2-4:25