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85% Arcing Current
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Author:  Jim Phillips (brainfiller) [ Sun Apr 17, 2011 5:52 pm ]
Post subject:  85% Arcing Current

IEEE 1584 suggests that an additional incident energy calculation should be performed using 85% of the arcing current for systems less than 1000 volts. This is to determine if the upstream protective device will still trip instantaneously during an arc flash.

Do you use the 85% value as part of your calculations?

Yes - we use 85% as well as 100%
No - we only use 100%
Other - we use a value other than 85%

Author:  jimmorton [ Wed Jun 01, 2011 11:16 am ]
Post subject: 

Yes - we use 85% as well as 100% .

We are mostly concerned with low voltage 450 Volt used on Navy ships. It has made significant diferences in some cases. 27 Cal/cm² vice 8

Jim

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