Short circuit calculation - on shipboard installations

[ritchieb]

I have been asked to complete a short circuit calculation for an installation on board a ship.

I have used DOC Win from ABB and selected the IEC 61363-1 option.

I also ran the calc using the DOC Win symmetrical components method. The results are very different ie: 15kA with the symmetrical method and 33 kA with the IEC 61363 method.

I don't have a copy of the IEC 61363 standard. Can anyone advise the method IEC 61363 uses so I can understand why the results are so different.

Thanks

 

[magoo2]

Rather than finding out why the results are different, have you done any simplified calculations on your own to see what you should expect?

Just take a simplified portion of the system and see what you get.

 

[waross]

A suggestion;
One calculation may be yielding an asymmetrical current.
The other may be yielding Available Short Circuit Current. Available Short Circuit Current calculations ignore the DC offset. The ASCC is used to size equipment. The equipment is tested and rated accordingly.

Bill
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"Why not the best?"
Jimmy Carter