Preface:

This is the second edition of CSA IEC 61558-2-1, Safety of power transformers, power supplies, reactors and similar products — Part 2-1: Particular requirements and tests for separating transformers and power supplies incorporating separating transformers for general applications, which is an adoption without modification of the identically titled IEC (International Electrotechnical Commission) Standard 61558-2-1 (second edition, 2007-01). It supersedes the previous edition published in 2003 as CAN/CSA-E61558-2-1 (adopted IEC 61558-2-1:1997), Safety of power transformers, power supply units and similar — Part 2: Particular requirements for separating transformers for general use.

This Standard is intended to be used in conjunction with CAN/CSA-E61558-1:12, Safety of power transformers, power supplies, reactors and similar products — Part 1: General requirements and tests (adopted IEC 61558-1:2005+A1:2009, with Canadian deviations).

This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.

Scope:

This part of IEC 61558 deals with safety aspects of separating transformers and power supplies incorporating separating transformers such as electrical, thermal and mechanical safety.

This Part 2-1 is applicable to separating transformers and power supplies incorporating both separating transformers and electronic circuits. This Part 2-1 is not applicable to external circuits and their components intended to be connected to the input terminals, output terminals or socket-outlets of the transformers and power supplies.

This Part 2-1 does not apply to transformers covered by IEC 60076-11.

This Part 2-1 applies to stationary or portable, single-phase or polyphase, air-cooled (natural or forced) independent and associated separating transformers and power supplies, having a rated supply voltage not exceeding 1 000 V a.c., a rated supply and internal operating frequency not exceeding 500 Hz.

The rated output does not exceed:

• 1 kVA for single-phase separating transformers and single-phase power supplies incorporating separating transformers;
• 5 kVA for poly-phase separating transformers and poly-phase power supplies incorporating separating transformers.

This Part 2-1 is applicable to separating transformers and power supplies incorporating separating transformers without limitation of the rated output subject to an agreement between the purchaser and the manufacturer.

This Part 2-1 is applicable to dry-type transformers. The windings may be encapsulated or non-encapsulated.

The no-load output voltage or the rated output voltage does not exceed 1 000 V a.c. or 1 415 V ripple-free d.c. For independent separating transformers and independent power supplies, the no-load output voltage and / or the rated output voltage is not less than 50 V a.c., or 120 V ripple-free d.c.

Separating transformers covered by this Part 2-1 are used only in applications where double or reinforced insulation between circuits is not required by the installation rules or by the end product standard.

NOTE 1 Normally, the separating transformers and power supplies incorporating separating transformers are intended to be used with equipment to provide voltages different from the supply voltage for the functional requirements of the equipment. The protection against electric shock may be provided (or completed) by other features of the equipment, such as the body. Parts of output circuits may be connected to the input circuits or to protective earth.

This Part 2-1 is applicable to separating transformers and power supplies incorporating separating transformers associated with specific equipment, to the extent decided upon by the relevant IEC technical committees.

NOTE 2 Attention is drawn to the following:

• for separating transformers and power supplies incorporating separating 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 separating transformers and power supplies incorporating separating transformers should also be considered;
• additional requirements in accordance with other appropriate standards and national rules may be applicable to separating transformers and power supplies incorporating separating transformers intended for use in special environments, such as tropical environment.

NOTE 3 Future technological development of separating transformers and power supplies incorporating separating transformers may necessitate a need to increase the upper limit of the frequencies, until then this Part 2-1 may be used as a guidance document.