scope:

This international standard is applicable to a.c. circuit-breakers designed for indoor or outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 1000 V. It is only applicable to three-pole circuit-breakers for use in three-phase systems and single-pole circuit breakers for use in single-phase systems. Two-pole circuit-breakers for use in single-phase systems and application at frequencies lower than 50 Hz are subject to agreement between manufacturer and user. This standard is also applicable to the operating devices of circuit-breakers and their auxiliary equipment. However, a circuit-breaker with a closing mechanism for dependent manual operation is not covered by this standard, as a rated short-circuit making-current cannot be specified, and such dependent manual operation may be objectionable because of safety considerations. This standard does not cover circuit breakers intended for use on motive power units of electrical traction equipment; these are covered by IEC 60077. Generator circuit-breakers installed between generator and step-up transformer are not within the scope of this standard. Switching of inductive loads is covered by IEC 61233. Circuit-breakers with an intentional non-simultaneity between the poles, with the exception of circuit-breakers providing single-pole auto-reclosing, are not within the scope of this standard. This standard does not cover self-tripping circuit-breakers with mechanical tripping devices or devices which cannot be made inoperative.