Short circuit current abbreviations (ICC)

[Area]

Dear all,

can anyone give an explanation of ICC? I found it very often in technical documentation of electrical equipment but nobody (also not the vendors of the equipment) could give me a reasonable explanation. Very often, they get confused with other abbreviations like ICM, ICU, ICW. For these abbreviation I found the following explanations:

ICM: Rated short-circuit making capacity
ICM (peak kA) is the maximum value of the asymmetrical short-circuit current that the device can carry. For a circuit-breaker, the stress to be managed is greatest on closing on a short-circuit.

ICU: Rated ultimate breaking capacity
ICU (kA rms) is the maximum short-circuit current value that a circuit-breaker can
break. It is verified according to a sequence of standardized tests. After this sequence, the circuit-breaker must not be dangerous. This characteristic is defined
for a specific voltage rating UE.

ICS: Rated service breaking capacity
ICS (kA rms) is given by the manufacturer and is expressed as a % of lCU. This
performance is very important as it gives the ability of a circuit-breaker to provide
totally normal operation once it has broken this short-circuit current three times. The higher lCU, the more effective the circuit-breaker.

ICW: Rated short time withstand current
ICW (kA rms) is the maximum short-circuit current that the device can withstand for a short period of time (0.05 to 1s) without its properties being affected. The time is mentioned together with the current. Normal time values are 1s or 3s. ICW (1s) is usually higher than ICW (3s), as ICW is referring to the thermal stress of advice. This performance is verified during the standardized test sequence.

 

[jbartos]

Suggestion: Visit

http://www.memonline.com/mpseight.html

http://www.bill-switchgear.com/tm_cbs.html

http://www.electrak.co.uk/busbar/datasheet.asp

http://www2.siemens.no/multimedia/archive/00750/8PT_Withdrawable_750394a.pdf

for: Icc - Conditional Short Circuit Breaking

 

[vtakev]

Hi! Use the fllowing definitions:
Short - circuit is the accidental or deliberate connection across a comparatively low resistance or impedance between two or more points of a circuit which usually have deiffering voltage. Therefore short circuit current Icc 0s the current in an electrical circuit in which a short-circuit occurs.
In human language this means that Icc is the current which will appear in a given point of electrical circuit in case of short-circuit in this place. In Lv isntalations you can meet also "Prospective Icc" which is the maximum short circuit current of this isntallation i.e. on the transformers terminals.