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 1 000 V.
It is only applicable to three-pole circuit-breakers for use in three-phase systems and singlepole 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 to 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 [4]1).
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.
By-pass circuit-breakers installed in parallel with line series capacitors and their protective equipment are not within the scope of this standard, these are covered by IEC 60143-2 [6].