KA Ratings of Breakers

So little information has been supplied. Do you mean how to increase the maximum short circuit (or fault) rating of a circuit breaker?

If so, like a fuse you cannot. Either use a circuit breaker with a suitable rating or limit the maximum current going thru the circuit breaker. More options may be available to you, but you will need to look in your local electrical regulations and standards to see what is allowed (there may be a work-around solution depending on your application).

What's the application (did you upgrade your site capacity increasing your maximum possible short circuit current, which now exceeds your circuit breaker capacity)?

Dear Sir,

Greetings...thanks for your reply. But iam not satisfied with your answer. Let me explain clearily what is requirement is . If I have already used 1KA breaker(say MCB) where 4KA breaking capacity is required. What I have to do if I want to increase the breaking capacity of my breaker(provided am not going to replace the breaker with higher breaking capacity which i actually required). Using that same breaker I have to acheive my breaking capacity(4KA).

Can you please provide the solution for this?

You have to either limit the prospective short circuit current to a value less than the limits of your breaker or replace the breaker with a suitably-rated one. You cannot increase the breaking capacity of a standard sealed MCB!

Check your electrical standards for clarification. If you ordered the wrong MCB's then you need to send them back or move them to circuits which have a lower fault current and buy suitably rated MCBs. There is no cheap workaround and you cannot add fuses (which operate slower than the circuit breakers, check the fuse and circuit breaker trip curves for clarification).

For more clarification consult a qualified local electrician or electrical engineer.

Hello Prem,

I do not believe there is any way to increase the KA ratings of the breaker. If you are exceeding the fault ratings on your switchgear, you may either replace the switchgear with higher ratings / introduce reactors in the circuit (which may lead to voltage regulation problems and drop in efficiency) or use some advanced current limiting protection devices that can limit the fault energies going into the system.

More details will help give a comprehensive feedback.

Amit.

I understand your question, because I had the same question.

The answer is:

To use proper dimensions of the special contacts, of the class called un-weldable. You can find then on the specialised market. One example: Ag(silver) -CADMIUM OXIDE

To provide the breaking moving contacts of electrical arc dividers and extinguishers. Look for that on CR4 and in Google.

Good luck

Arturo

Can I have examples of advanced current limiting protection devices please ?

Also I came to know from other sources that I can use fuses of what the KA rating which I required across the breaker in order to increase/acheive the breaking capacity of my breaker. Is it true?