This part of IEC 60898 applies to a.c. air-break circuit-breakers for operation at 50 Hz or 60 Hz, having a rated voltage not exceeding 440 V (between phases), rated current not exceeding 125 A and a rated short-circuit capacity not exceeding 25 000 A.


As far as possible, it is en line with the requirements contained in IEC 60947-2.


These circuit-breakers are intended for the protection against overcurrents of wiring installations of buildings and similar applications; they are designed for use by uninstructed people and for not being maintained.


They are intended for use an environment with pollution degree 2.


They are suitable for isolation.


Circuit-breakers of this standard with exception of those rated 120 V or 120/240 V (see table 1), are suitable for use in IT systems provided that the requirements of IEC 60364-4-473:1977 + A1:1998 are complied with.


This standard also applies to circuit-breakers having more than one rated current, provided that the means for changing from one discrete rating to another is not accessible in normal service and that the rating connot be changed without the use of a tool.


This standard does not apply to


-- circuit-breakers intended to protect motors;

-- circuit-breakers, the current setting of which is adjustable by means accessible to the user.


For circuit-breakers having a degree of protection higher than IP20 according to IEC 60529, for use in locations where ardous environmental conditions prevail (e.g. excessive humidity, heat or cold or dispostion of dust) and in hazardous locations (e.g. where explosions are liable to occur), special constructions may be required.


Rerquirements for circuit-breakers for a.c. and d.c. operationa re given in IEC 60898-2.


Requirements for circuit-breakers which incorporate residual current tripping devices are to be found in IEC 61009-1, IEC 61009-2-1, and 61009-2-2.