Chapter 9 table 8
- Thread starter pedro1200
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OldBroadcastTech
Senior Member
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- Western IL
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- Retired Broadcast Technician
not sure but maybe this will help
www.unitconverters.net
Convert Circular Mil to Square Inch
Instant free online tool for circular mil to square inch conversion or vice versa. The circular mil to square inch [in^2] conversion table and conversion steps are also listed. Also, explore tools to convert circular mil or square inch to other area units or learn more about area conversions.
www.unitconverters.net
I still will like to learn the full application of the tablenot sure but maybe this will help
Convert Circular Mil to Square Inch
Instant free online tool for circular mil to square inch conversion or vice versa. The circular mil to square inch [in^2] conversion table and conversion steps are also listed. Also, explore tools to convert circular mil or square inch to other area units or learn more about area conversions.
- Location
- Chapel Hill, NC
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- Retired Electrical Contractor
In table8 chapter 9 is for the conductor size without the insulation. When comparing conductors one would use the cir.mil. Personally, I have never used the sq.in column for conductor properties.
When doing conductor fill I would use sq. in. But that would be in the other tables based on the insulation size.
When doing conductor fill I would use sq. in. But that would be in the other tables based on the insulation size.
From Google
The main difference is that
circular mils (cir mils or CM) is a specialized unit of area for measuring the cross-section of circular wires, while square inches (sq. in or in²) is a standard, general-purpose unit of area. The circular mil system simplifies calculations by absorbing the value of
πpi into its definition.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
There are 2 things going on.
First: Circular mils and square inches are both units of area.
A square inch is just the area of a square 1 inch on the side. A circular mil is just the area of a circle 1 mil in diameter. There are 1273240 circular mils in 1 square inch. You can measure any area in circular mils or square inches or mm2 or acres or whatever. Circular mils are pretty much only used for measuring the conductive cross section of wires.
Second: the two columns are reporting two different areas. The area column to the left reports the conductive cross section of the conductor, how much is there to actually carry current. The area column to the right reports the area taken up by the conductive material including any space between the strands; it is essentially the fictional area of a circle that just encloses the strands of wire.
You will note that for the solid conductors the 'left' area and the 'right' area are the same when reported in mm2, and if you calculate it out and account for significant figures the numbers also match in circular mils/ in2. For stranded conductors you will note that 'right' area is larger than the 'left' area, because of the spaces between the strands. At the same time the 'left' area column is exactly the same for solid and stranded of the same gauge.
First: Circular mils and square inches are both units of area.
A square inch is just the area of a square 1 inch on the side. A circular mil is just the area of a circle 1 mil in diameter. There are 1273240 circular mils in 1 square inch. You can measure any area in circular mils or square inches or mm2 or acres or whatever. Circular mils are pretty much only used for measuring the conductive cross section of wires.
Second: the two columns are reporting two different areas. The area column to the left reports the conductive cross section of the conductor, how much is there to actually carry current. The area column to the right reports the area taken up by the conductive material including any space between the strands; it is essentially the fictional area of a circle that just encloses the strands of wire.
You will note that for the solid conductors the 'left' area and the 'right' area are the same when reported in mm2, and if you calculate it out and account for significant figures the numbers also match in circular mils/ in2. For stranded conductors you will note that 'right' area is larger than the 'left' area, because of the spaces between the strands. At the same time the 'left' area column is exactly the same for solid and stranded of the same gauge.
Speedskater
Senior Member
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- Cleveland, Ohio
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- retired broadcast, audio and industrial R&D engineering
Is there a link to the complete chart?
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research