Bus bar ampacity/ auxiliary gutters?

[cwain]

In 366.23 the formula (1000 amperes/in.2). Does this mean 1000 amps per sq. inches of bus bar. Or does it mean 1000 amps divided by inches of bus bar squared.

If copper bus bar is 1/2 in. x 4in what would be the ampacity?

 

[szrom]

Bus bar ampacity

Bus bar ampacity

366.23 means 1000A per square inch of bus bar. A 1/4" by 4" bus bar is equal to 1 sq inch which can carry 1000A. A 1/4" by 6" bus bar is equal to 1.5 sq inches which means 1000A x 1.5 = 1500A.

 

[Rockyd]

1000 Amps per square inch for Cu.

4" x 1" x .5" = 2"

That's the way I read it.

 

[charlietuna]

A 1/2 inch thick, by 4 inch wide copper bus bar should be 2 square inches relating to a capacity of 2000 amperes

 

[Besoeker]

A figure of 1000A/ in^2 is often used in UK as a rule of thumb.
But the profile of the bar also has a bearing on the current carrying capacity.
For example a 4in by 1/4 in bar can carry about 23% more current than a 2 in by 1/2 bar for the same temperature rise even though both have the same 1.0 sq inch cross sectional area.

Note that this refers to current carrying capacity, not the permitted rating in accordance with specific codes that may apply.

 

[szrom]

But the profile of the bar also has a bearing on the current carrying capacity.
For example a 4in by 1/4 in bar can carry about 23% more current than a 2 in by 1/2 bar for the same temperature rise even though both have the same 1.0 sq inch cross sectional area.

Besoeker: Thanks for this. Do you have any reference materials (online or printed) that you could refer me to? I have been looking for this kind of information.

 

[Smart $]

Besoeker: Thanks for this. Do you have any reference materials (online or printed) that you could refer me to? I have been looking for this kind of information.

http://www.copper.org/applications/busbar/homepage.html