Safety of Power Transformers, Power Supply Units and Similar - Part 2-2: Particular Requirements for Control Transformers
|Publication Date:||1 January 2007|
|ICS Code (Transformers. Reactors):||29.180|
This part 2-2 of IEC 61558 applies to stationary or portable, single-phase or poly-phases, air-cooled control transformers associated or otherwise having a rated supply voltage not exceeding 1 000 V a.c. or 1 415 V ripple free d.c. and rated frequency not exceeding 500 Hz and no limitation of the rated output.
This standard is applicable to transformers used between circuits where double or reinforced insulation is not required by the installation rules or by the equipment specification.
This standard is applicable to dry type transformers. The windings may be encapsulated or non-encapsulated.
NOTE 1 - Normally, these transformers are intended to be associated with equipment to provide voltages different from the supply voltage for the functional requirement of the equipment. The safety insulation 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 circuit or to protective earth.
NOTE 2 - For transformers filled with liquid dielectric or pulverised material, such as sand, additional requirements are under consideration.
NOTE 3 - In locations where special environmental conditions prevail, particular requirements may be necessary in accordance with IEC 60364-5-51.