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Breaking Capacity OF MCCB

09/29/2013 12:56 AM

How to calculate the breaking capacity of MCCB used for 100 KVA,415 Volt generator. If we dont know the actual load at coustomer end?

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#1

Re: Breaking Capacity OF MCCB

09/29/2013 1:19 AM

How big are the wires?

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#2
In reply to #1

Re: Breaking Capacity OF MCCB

09/29/2013 4:15 AM

It is 50 sq.mm and 1200 mm in length.

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#3
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Re: Breaking Capacity OF MCCB

09/29/2013 9:05 AM

You miss the point here. This site has no responsibility to give instruction to those incapable of performing a reasonably simple task.

If you can't do your own work, safely, you should not be involved in the task.

We don't read minds here and we don't know what codes are in effect wherever you may happen to be.

Breaking capacity - Wikipedia, the free encyclopedia

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#5
In reply to #2

Re: Breaking Capacity OF MCCB

09/29/2013 11:05 PM

Did I hit a nerve?

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#7
In reply to #2

Re: Breaking Capacity OF MCCB

09/30/2013 6:16 AM

As in 1.2m? How on earth does one not know the load of something that is 4-5ft away?

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#8
In reply to #7

Re: Breaking Capacity OF MCCB

09/30/2013 9:27 AM

To know, is no longer important. To have someone furnish the answer, is the way of the new "engineer".

You may quote me on that.

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#11
In reply to #8

Re: Breaking Capacity OF MCCB

09/30/2013 11:03 AM

Many already do.

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#4

Re: Breaking Capacity OF MCCB

09/29/2013 10:31 PM

Please see your local electrical regulations. The nominal CB rating will be somewhere around 2x the genset's FLA.

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#6

Re: Breaking Capacity OF MCCB

09/30/2013 3:51 AM

Simple. Use the local code book. In the UK, it would be British Standard 7671.

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#9

Re: Breaking Capacity OF MCCB

09/30/2013 10:06 AM

Please refer earlier discussion in CR4 : http://cr4.globalspec.com/thread/44521 posted on 10/9/2009, on topic 'how to size the MCCB breaking capacity (KA) from the load?"

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#12
In reply to #9

Re: Breaking Capacity OF MCCB

09/30/2013 11:04 AM

That makes this thread a duplicate, and reportable to Admin.

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#14
In reply to #9

Re: Breaking Capacity OF MCCB

10/01/2013 9:13 AM

Thanx!

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#10

Re: Breaking Capacity OF MCCB

09/30/2013 10:54 AM

100kVA generator at 415 V, the rated current would be 140A. Assuming a sub-transient reactance of about 10% for the generator, the fault level would be about 1400A. You may go for a 10kA or a 16kA MCCB.

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#13
In reply to #10

Re: Breaking Capacity OF MCCB

09/30/2013 11:05 AM

..."if that assumption were correct".

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#15
In reply to #10

Re: Breaking Capacity OF MCCB

10/27/2013 12:19 AM

Thanks For the information , it will help me!

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