I was looking for a program to calculate the current rating
of various bus bars combination and sizes. I have dowloaded
your program busbar32.exe and examined the tab Busbar-Rating.
Your program seems ok for single bars but to be usefull it
should state the underlying assumptions such as frequency and
I noticed that if you set the ambiant to 90deg C, you get a
rating of 0 for aluminum and a rating for copper. This seems
to be wrong since aluminum rating would be approximately 62%
(depending on conductivity) of the copper rating.
The reason you get the 0 rating for aluminium at 90 degrees and 0 for copper at 105 degrees is that the standards call for a maximum operating temperature for Aluminium of 90 degrees C and for copper of 105 degrees C. If the ambient temperature is equal to the maximum operating temperature, then the current must be zero. Any current would result in a temperature rise above the set limit.