Recent content by chairmounted

Good stuff.....thanks for the responses. stevenal: I don't have that book, but it sounds like I should get it. any chance that you could list a few more examples from the Westinghouse book with different voltage imbalances and power factors? Once again, thanks for the responses.

I'm in the USA.

Can anyone quantify the accuracy of a form 9S vs. 5S metering installation?

Thanks for the responses. I didn't think of the tolerance and 1.3 factor. So if I enter the time curve data of the Short Delay curve, do I enter the trip time at the max 'arcing current' and then again at the 85% max 'arcing current' or do I have to enter many points to determine the worse...

Thanks for responding. I'll try to explain better. At the LV breaker the max bolted fault current is 21.94kA and the calculated(by IEEE spreadsheet) arcing current is 12.83kA. 85% of 12.83 is 10.91kA. The existing instantaneous trip setting is 18kA, so I change the instantaneous trip setting...

I am using IEEE 1584 spreadsheet to calculate the arc flash energy downline from a low voltage circuit breaker. The maximum available fault current is 26kA and the Digitrip is set to 18kA instaneous trip. The cell in the spreadsheet turns orange noting 'out of range'. What range are they...