Conductors

[pedro1200]

In chapter 9 table 5 you have approximate area and approximate diameter. How does approximate diameter differs from approximate area?

 

[Eddie702]

They are 2 completley different things.

The diameter of a circle is if you take a ruler and measure straight across the middle from the outside of the circle to the outside of the circle. So a circle that measures 2" outside to outside would have a 2" diameter

To find the area of that 2" circle you multiply 2" x 2"=4" and multiply 4" x .7854= area

So a 2" circle area would be (2 x2) x .7854=3.1416 square inches

Area is used to size conduit for wire fill

 

[ggunn]

In chapter 9 table 5 you have approximate area and approximate diameter. How does approximate diameter differs from approximate area?

A = (pi)r^2 where r is the radius = diameter / 2

 

[Speedskater]

In chapter 9 table 5 you have approximate area and approximate diameter. How does approximate diameter differs from approximate area?

If the conductor is not approximately round.

 

[charlie b]

How does approximate diameter differs from approximate area?

The code writers have to use "approximate" values, because exact values cannot be obtained. There will always be slight differences between various manufacturers. Also, if you wish to use the formula in post #3, what value do you use for "pi"? Do you use 3.14, or perhaps 3.14159, or 3.1415926535, or a value even more nearly precise?

 

[don_resqcapt19]

The code writers have to use "approximate" values, because exact values cannot be obtained. There will always be slight differences between various manufacturers. Also, if you wish to use the formula in post #3, what value do you use for "pi"? Do you use 3.14, or perhaps 3.14159, or 3.1415926535, or a value even more nearly precise?

Assuming I have a calculator, I just use what ever number of places the π symbol generates...same for the square root of 3...I always put in 3 and push the square root button.