Wat betekenen Icu, Ics, Icw en Icm?

Bij vertalingen van normen kunnen afkortingen verkeerd geïnterpreteerd worden. Om dat te voorkomen, staan hieronder de originele teksten vermeld. Deze gegevens zijn ook terug te vinden in de internationale Standards IEC 60947-1, IEC 60947-2 en IEC 60947-3.

Icu
Rated ultimate short-circuit breaking capacity (Icu ) The rated ultimate short-circuit breaking capacity of a circuit-breaker is the maximum short-circuit current value which the circuit-breaker can break twice (in accordance with the sequence O – t – CO), at the corresponding rated operational voltage. After the opening and closing sequence the circuit-breaker is not required to carry its rated current.

Ics
Rated service short-circuit breaking capacity (Ics ) The rated service short-circuit breaking capacity of a circuit-breaker is the maximum short-circuit current value which the circuit-breaker can break three times in accordance with a sequence of opening and closing operations (O - t - CO - t – CO) at a defined rated operational voltage (Ue ) and at a defined power factor. After this sequence the circuit-breaker is required to carry its rated current.

Icw
Rated short-time withstand current (Icw ) The rated short-time withstand current is the current that the circuit-breaker in the closed position can carry during a specified short time under prescribed conditions of use and behavior; the circuit-breaker shall be able to carry this current during the associated short-time delay in order to ensure discrimination between the circuit-breakers in series.

Icm
Rated short-circuit making capacity (Icm ) The rated short-circuit making capacity of an equipment is the value of short circuit making capacity assigned to that equipment by the manufacturer for the rated operational voltage, at rated frequency, and at a specified power-factor for ac.