%DC Component of Circuit Breaker Breaking Capacity.

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Orlyboy

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Deal All,

What will be the %DC of the Circuit Breaker Breaking Capacity.
The data is needed in generating Datasheet fo HV Switchgear as per IEC standard.

Is there any step by step calculation to determine the %DC Breaking Capacity?

Thank you!
 
Orlyboy said:
Deal All,

What will be the %DC of the Circuit Breaker Breaking Capacity.
The data is needed in generating Datasheet fo HV Switchgear as per IEC standard.

Is there any step by step calculation to determine the %DC Breaking Capacity?

Thank you!
Click to expand...

Have you contacted the manufacture? I found it common fot those to avoid asking a manufacture as it appears there may be the fear of getting an answer that they don't want to hear. I worker for a major electrical distribution protection and control manufacture for 18 years as a sales and as application engineer and I had found no issues to consult with my design engineers to get the type of information that you are requesting. In general because AC current cycles through zero volts twice a cycle that is a major factor in the ability to clean an arc which DC current doesn't do. As such if the device is even capable of clearing a DC arc one is to expect a significantly lower voltage tasting an interrupting capacity. I highly doubt if there are means to use calculations to returning DC ratings rather than the use of actulat testing.
 
templdl said:
Have you contacted the manufacture? I found it common fot those to avoid asking a manufacture as it appears there may be the fear of getting an answer that they don't want to hear. I worker for a major electrical distribution protection and control manufacture for 18 years as a sales and as application engineer and I had found no issues to consult with my design engineers to get the type of information that you are requesting. In general because AC current cycles through zero volts twice a cycle that is a major factor in the ability to clean an arc which DC current doesn't do. As such if the device is even capable of clearing a DC arc one is to expect a significantly lower voltage tasting an interrupting capacity. I highly doubt if there are means to use calculations to returning DC ratings rather than the use of actulat testing.
Click to expand...
Or are you (OP) perhaps thinking of the DC component within an AC fault? This is something that I believe is internally factored into the classification of fault interrupting capacity by virtue of it being part of the standardized test criteria, but as far as I know it is not something I have ever seen specified in the selection of switchgear, nor would I imagine it to be a variable from one brand to another, so I've never heard of a formula for calculating it.
 
Jraef said:
Or are you (OP) perhaps thinking of the DC component within an AC fault? This is something that I believe is internally factored into the classification of fault interrupting capacity by virtue of it being part of the standardized test criteria, but as far as I know it is not something I have ever seen specified in the selection of switchgear, nor would I imagine it to be a variable from one brand to another, so I've never heard of a formula for calculating it.
Click to expand...
Wouldn't it be helpful of the OP would reply with a clarification? It is as if a vague question is asked and then replys are based upon quessing what the OP is asking, a guessing game.
Also, quite often there is no information provide whether or not the question is based upon a theoretical application of a true field application the needs to be addressed.
 
%DC Component of Circuit Breaker Breaking Capacity

%DC Component of Circuit Breaker Breaking Capacity

The data is needed in the HV Switchgear Datasheet.
Please see attached file.

CB BreakingCapacity1.JPG

Thank you for all the inputs.
 
%DC Component of Circuit Breaker Breaking Capacity.

Image attached is extracted from 62271-100 IEC:2008+A1:2012.

CB BreakingCapacity2.JPG
Thank you..
 

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iwire said:
And here I have been thinking it would be helpful if you stopped always complaining about people's posts.
Click to expand...

Thanks for the reply from the OP. Now that I see what he is referring to I would highly suggest that he contact the manufacture. It must be assured that the contact has the relationships and wherewithall to get the answers. At on time I would have been that point of contact who had a relationship with design engineers that I could rely on to get accurate data from. Some of this type of information is not published or it may not even exist. As good design engineers they would have been able to retrieve such information of do ther calculations. It is those design engineers that provide the design support for the product which I could then provide to my customer.
It is not all that unusual that such specs are copied and pasted from another source without any thought about if they actually relavent or not.
 
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