BS EN 61558-2-1:2007 Safety of power transformers, power supplies, reactors and similar products - Particular requirements and tests for separating transformers and power supplies incorporating separating transformers for general applications
Replacement:
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.
BS EN 61558-2-1:2007 history
2006BS EN 61558-1:2005+A1:2009 Safety of power transformers, power supplies, reactors and similar products — Part 1: General requirements and tests
2006BS EN 61558-1:2005 Safety of power transformers, power supplies, reactors and similar products - Part 1: General requirements and tests
1998BS EN 61558-1:1998 Safety of power transformers, power supply units and similar - General requirements and tests
1996BS EN 60742:1996 Isolating transformers and safety isolating transformers - Requirements