Short Circuit Capacity Prediction

You might want to have a look at atp-emtp, an open source package that might be able to do what you are trying to accomplish.

Have a look at Schneider EcoDial S which is free:

http://www.soft.schneider-electric.com/myecodialS.htm

and of course only relates to Schneider breakers.

This is a light version of EcoDial L which is free to professionals but you must order it through your local agent.

The Circuit breaker can be checked through Special circuit breaker testing kits from Megger where exact short circuit conditions can be predicted in the lab. it can also be checked using advanced softwares such as Etap, C-grid, etc. We can also do calculations its a tedious process but if you are a engineering graduate you can get the formulas in the text book on power system studies written by various authors.

All C/B manufacturers publish sets of curves relating SC current & trip time. After all it's necessary to plan the discrimination between protective devices.

Just ask your supplier.

Maybe i didn't word it properly. i am a designer of switchgear, ACBs and MCCBs among them. So, having made a design, i have no option but to make samples (an expensive process) and test them for Ics, Icw and Icu at high-power labs, another expensive process. My clients cannot afford to have such expensive labs of their own, so .. developing new circuit breakers is a long and tedious process. Since design can be done in 3D CAD, and analysis can be done using FEA and dynamic analysis software, i am hoping to get some predictive software for arc also, so that we can design first-time-right.

My response was incomplete..sorry.

About the contact material : In MCCBs, these are usually AgSnO2 or AgW or AgWC, whose properties are (a) high arc mobility so that the arc roots quickly move all over the surface distributing the pitting, and also transfer to the de-ion grids quickly, and (b) they are hard, and do not suffer much erosion due to the high current arc.

About the contact design itself: In ACBs, there are quite often replaceable arcing contacts made of AgW and main contacts which do not see any arcing made from AgNi or such high conductivity materials which operate cool under rated current. In MCCBs though, no replaceability is possible so the materials i mentioned before are used. i hope this helps.

If you already knew this, my apologies in presuming that you didn't know