Arc Flash ANSI vs Comprehensive calculation method

Question:
What is the difference between the ANSI and comprehensive calculation that leads ANSI to be so much higher? And if this method has a higher value, shouldn’t the Arc flash model being using it?

Answer:

Please refer to the link below. It also has a link to a pdf with detailed comparison.

Basically, A_Fault calculation methodology has equipment multipliers which will result in higher fault duties.

Arc flash calculations consists of several factors. Two of which is fault duties and trip/delay time. A higher fault duty generally results in a faster trip time and lower arc flash results.

In other words, higher fault duties will not give you worst arc flash results. The comprehensive fault method is more conservation for arc flash purposes.

http://www.skm.com/afault.html

Creation date: 3/28/2016 3:13 PM     Updated: 3/28/2016 3:21 PM