Fault Level of System in kA

Industrial power engineering and applications handbook...

As usual, you apparently have no clue about what you are doing.

I suggest you go back to school (if you ever went there in the first place) or find a job that is within your current capabilities.

Or, at least learn how to search the internet to learn THE BASICS before you blow something up or kill someone. "Searching the web" does not mean asking CR4 members to provide you with an education.

How to Search the Web and Find What you Want

I am beginning to wonder if we're doing society a disservice by preventing the truly clueless from failing in a spectacular fashion. I'm not talking solely about the granting of Darwin awards. A Darwin award does serve a social good by trimming the gene pool. I'm referring to the much more common failures where the clueless wastes time and money trying to do something beyond their skills. So very often this leads to much more time and money being spent than if it was done correct in the first place by somebody that knows what to do. People won't appreciate the value of good schooling until they have to pay for ignorance.

It may be time to start another list.

The first list I started was to identify people who come here, ask a question, and then refuse to accept the explanations of experts offered here. They insist that we furnish documented evidence, "with examples" that support us.

Now, I believe it is time to start a new section here on CR4. I like the name "Tutor time". This would be for those students and jobholders who are clueless, and want us to teach them the basics.

There are some members who qualify for charter memberships, and many APs who do.

I'm afraid that the gene pool here, for some, is beginning to look primordial.

I'm watching a NASCAR race now. 210MPH in a "stock" car seems very fast to me.

You're just itching to get your hands on another one.

November 18th. I can't wait!

Don't forget the insurance.

I never got the in-car video from the last wreck session.

They claimed they lost it when they moved their office later that same week. I suppose it's possible.

As a consession, they're giving me 50% off on the session price and a free video this time. I'll post it _{if I get it.}

You are certainly entitled to your opinion. It is worth just as much as mine, here.

However, I am not masquerading as an electrician.

Here's a selection of your "contributions" to the forum:

1. "Kindly tell me that how much torque a 3 phase motor of 7.5 KW and 1500 RPM will have in Nm."

2. "I have ordered PCIe Gen.2 VGA Card. Now its been purchased. Kindly help me to verify that it is Gen.2.0 or Gen.1.0 by just seeing the VGA Card. Its make is NVIDIA. Its PCB is green coloured."

3. "Kindly tell me that if I can use 1.5 mm cable for starting of single Phase Exhaust fan Motor through DOL."

4. "Can anyone tell me the difference between directional sensitive earth fault and non directional sensitive earth fault"

Your comment about the color of the circuit board in #2 says it all.

There may be others here who are willing to tutor you. I am not.

Cheers.

schneider Electric Short Circuit Calculation

70kA MCCB can be used for systems having a fault rating of less than 70KA

50KA MCCB can be used for systems having a fault rating of less than 50KA.

Another option for iPhone app to do the calculation

http://itunes.apple.com/us/app/transcalc/id350747030?mt=8

You are welcome to ask a question at any time.

But please take on board we are not a substitute for Google when it comes to stupid and inane questions.

We are independent engineers with probably 1000's of years of experience bewteen us. Most of that experience didn't come from the Internet, it came from reading books and hands on hard work.

Our time is as valuable as is anyone else's, how we choose to use that time is our decision. Wasting it on the likes of you isn't one of my options.

Dear TonyS,

Hope you are doing great. Actually all the men are not expert and the knowledge varies as well as skills. I started this thread to know how to calculate the fault level of the system but a mad person like Iyn had gone astray to point personal attacks. You are doing the same and it is your opinion. Other persons out there are helping me as far as they can.

Hi AA039

based on the way you question is structured, i do get the frustration expressed by the guys, but i will not entertain that.

there are couple of power systems books that can help you understand the system fault levels e.g. N e t w o r k P r o t e c t i o n & A u t o m a t i o n G u i d e.

Generally, Fault level is greater near the source and it gets reduced as you move away from the source. A circuit breaker rating(kA) is a recommended rating by the manufacturer of the breaker based on the tests they conducted on that type of breaker. the kA rating is the amount of energy a CB can successfuly withstand during fault.

working out fault level at a particular point in the system helps in selecting a proper CB to be used for a better protection of your system. e.g. if you worked out that fault level at a busbar is 75kA, then this means any CB having a kA rating less than 75kA will not be suitable for application and the same applies to a 50kA CB.

regards,