Core size nomenclature 1

[Janus101]

Im used to the terminlogy "square millimetre" when expressing a core size. Some time ago I ran in to "AWG". I assume this to be American. Can someone shed some light how this sizing is used and what does it stand for?

Thanks.

 

[dpc]

American Wire Gage. The smaller the number the large the wire. Previously referred to as the Brown & Sharpe Gage.

There is a mathematical (geometric) progression -

Size 0000 is defined as 0.46 inches in diameter. Size 36 is defined as 0.0050 inches.

The ratio between any two adjacent sizes is 1.123

An increase of three sizes approximately doubles the cross-sectional area.

For sizes above 0000 (or 4/0), we use circular mils, which makes even less sense. A circular mil is a unit of AREA equal to the area of a circle that is 1 mil in diameter. (A mil is equal to 0.001 inches).

So to convert from circular mils to actual area:

1 circular mil = 0.7854 mils squared

We generally use kcmil (thousand circular mils), previously abbreviated as mcm.

Of course in the UK, you have British Standard Gauge....

 

[dbaird]

Check out:

http://www.awc-corp.com/TechNotes/TN_AWG_conversion.html

David Baird
mrbaird@hotmail.com

Sr Controls Engineer

EET degree.

Journeyman Electrician.

 

[Janus101]

Thank you both for your replies.

 

[busbar]

"MCM versus mm2" was recently a usenet topic. See

http://groups.google.com/groups?dq=&hl=en&lr=&ie=UTF-8&th=8c8caf0ca8c4407f