International Electrotechnical Commission

Railway applications   Electric equipment for rolling stock   Part 4: Electrotechnical components   Rules for AC circuit-breakers - Edition 1.0
 N 60077-4

Annotation

In addition to the general requirements of IEC 60077-2, this part of IEC 60077 gives rules for AC circuit-breakers, the main contacts of which are to be connected to AC overhead contact lines; the nominal voltage of these circuits being in accordance with IEC 60850.

This standard, together with IEC 60077-2, states specifically:

a) the characteristics of the circuit-breakers;

b) the service conditions with which circuit-breakers have to comply with reference to:

– operation and behaviour in normal service,

– operation and behaviour in short-circuit,

– dielectric properties;

c) the tests for confirming the compliance of the components with the characteristics under the service conditions and the methods to be adopted for these tests;

d) the information to be marked on, or given with the circuit-breaker.

NOTE 1 Circuit-breakers which are dealt with in this standard may be provided with devices for automatic opening under pre-determined conditions other than those of over-current, for example, undervoltage and reversal of power current. This standard does not deal with the verification of operation under such predetermined conditions.

NOTE 2 The incorporation of electronic components or electronic sub-assemblies into electrotechnical components is now common practice.