Thank you jghrist for your response. I expect the author of the article I referred to was using the operating parameters of a three phase "C" curve MCCB to come up with the ka rating of the supply. I will continue to review my reference material until I find the article again.
ps; I am in...
I have been reading a number of articles recently dealing with arc flash. In one of the articles I came across a statement advising that below a certain value of fault current (ka) and a certain size of circuit breaker it is not worth conducting an analysis as the category will be zero. I think...
Gentlemen,
Thank you for your input. I found the information I require in SAI Global publication HB178:2006: section in question below.
1.1.1 What is the highest category of electrical circuits you intend to measure?
Categories indicate the amount of energy available in the circuit. The higher...
I am interested in learning more about the classification of test instruments, i.e. Categories (Cat rating). What I am specifically interested in is the level of fault current that determines the category of meter.
All of the information I have found uses a diagram showing power flow from a...
Recently we installed NER's on three 11/0.433kv power transformers supplying a coal processing plant. This modification was performed to overcome a design fault that was not picked up till 2 years after commissioning. I have been informed that I require 2 pole circuit breakers on all single...
