Short Circuit Calculation

Surely the equipment manufacturers publish this sort of thing - the results of their testing? <sigh>

Is it wise to rely on a calculation from an anonymous user on an Engineering forum site? Not at those sort of currents!

The question is not clear.There is calculation to find out the short circuit at a particular busbar/node which depends on transformer capacity,percentage impedance of transformer.incoming supply fault level, cable impedance etc.I have not come across any calculation for a short circuit of circuit breaker.

The circuit breaker has to withstand the short circuit current for a particular period, this has to be designed by the manufacturer.

If clear question is posted, we can try and give proper solution.

There is nothing like short circuit rating of a circuit breaker.It is the short time with stand capacity of the breaker and is a designer's problem. It is not a simple calculation that can be simply stated in a formula in this forum. The manufacturer designs the rating depending up on the components they use for their product and they specify this designed value and with stand time of each model in their product catalogue for your selection depending on your requirement. Most of the cases the rating of breaking capacity and short time with stand capacity of a breaker are same but not necessarily so in all cases.

formula of breaking capacity of 40A MCCB

You must admit that one of the curses of the Internet is the proliferation of people who decide to just ask questions of others instead of actually doing the leg work to figure something out by themselves.

Some of the questions asked point to an extremely low level of discipline knowledge on the part of those asking the questions.

The <sigh> issued by PW Slack is warranted.

Hi Del,

you wrote:- "extremely low level of discipline knowledge", I disagree with that statement completely, Sorry.

It should have said "a complete lack of low level of discipline knowledge"!!

Have a great day! My English Grammar is not so good, but I am sure that you understand that I actually fully and completely support your comments!

Andy

Your English Grammer is so good I thought you were from London.

Renato,

Your question has shown up twice in today's forum. I posted a fairly complete answer on the other blog where you appeared as "guest".

Regards--JMM

Renato,

Your question has shown up twice in today's forum. I posted a fairly complete answer on the other blog where you appeared as "guest".

Regards--JMM

Hi Mr. Jmueller,

Thank you very much for sending Bussman reference materials.

I found it very interesting.

I hope you can still extend your help to me in the future.

Best Regards,

Renato

sir,

Please give me the basic calculation for short circuit calculation of AC circuit breaker up to 1200 AMpere rating.

thank you,

DEEPAK

I think some guests are making fun of us, who contribute to the forum,by posting the same question.There should be some way out for these happenings!