SNZ AS/NZS IEC 60947.2
Low-voltage switchgear and controlgear Part 2: Circuit-breakers
|Publication Date:||29 June 2015|
Scope and object
This standard applies to circuit-breakers, the main contacts of which are intended to be connected to circuits, the rated voltage of which does not exceed 1 000 V a.c. or 1 500 V d.c.; it also contains additional requirements for integrally fused circuit-breakers.
It applies whatever the rated currents, the method of construction or the proposed applications of the circuit-breakers may be.
The requirements for circuit-breakers which are also intended to provide earth-leakage protection are contained in Annex B.
The additional requirements for circuit-breakers with electronic over-current protection are contained in Annex F.
The additional requirements for circuit-breakers for IT systems are contained in Annex H.
The requirements and test methods for electromagnetic compatibility of circuit-breakers are contained in Annex J.
The requirements for circuit-breakers not fulfilling the requirements for over-current protection are contained in Annex L.
The requirements for modular residual current devices (without integral current breaking device) are contained in Annex M.
The requirements and test methods for electromagnetic compatibility of circuit-breaker auxiliaries are contained in Annex N.
Supplementary requirements for circuit-breakers used as direct-on-line starters are given in IEC 60947-4-1, applicable to low-voltage contactors and starters.
The requirements for circuit-breakers for the protection of wiring installations in buildings and similar applications, and designed for use by uninstructed persons, are contained in IEC 60898.
The requirements for circuit-breakers for equipment (for example electrical appliances) are contained in IEC 60934.
For certain specific applications (for example traction, rolling mills, marine service) particular or additional requirements may be necessary.
NOTE Circuit-breakers which are dealt with in this standard may be provided with devices for automatic opening under predetermined conditions other than those of over-current and undervoltage as, for example, reversal of power or current. This standard does not deal with the verification of operation under such pre-determined conditions.
The object of this standard is to state:
a) the characteristics of circuit-breakers;
b) the conditions with which circuit-breakers shall comply with reference to:
1) operation and behaviour in normal service;
2) operation and behaviour in case of overload and operation and behaviour in case of short-circuit, including co-ordination in service (selectivity and back-up protection);
3) dielectric properties;
c) tests intended for confirming that these conditions have been met and the methods to be adopted for these tests;
d) information to be marked on or given with the apparatus.