ACSR-795MCM and ACSR-795mm2 Conductors

To understand the differences in 795 MCM and 750 mm², you must understand the MCM and mm² are both measures of the conductors cross-sectional area … i.e., if you were to cut a piece off the conductor with a very sharp tool, how much cross sectional area you would be looking at.

mm² – is just what it looks like square millimeters, or 1/1,000,000 of a square meter. So this measure is referring to a area one millimeter by one millimeter squared.

So for:

• A solid bar 20 mm x 20 mm the area would be 20 * 20 or 400 mm².
• For a round bar 20 mm in diameter the area would be (πr²) π * 10², or about 314 mm².

MCM – is thousand circular mills, and is an old designation. A mill is 1/1000 of an inch, and a circular mill is the area of a circle of that size.

To avoid the metric "M" "k" confusion issue, the designation kcmil is now preferred for thousand circular mills ("kcmil" = "MCM").

So … both mm² and MCM are measuremt units of area, and 1 mm² = 1.97 MCM (or approximately 2 MCM).

1. What are the differences between ACSR-795MCM & ACSR-795mm2 conductors?

795 MCM will have almost twice the cross sectional area of 795 mm²

2. Why do we use the symbol "MCM" in this conductor?

MCM is not used for current day conductor designations, kcmil is the preferred designation for this conductor, where 1 MCM = 1 kcmil.

3. What does the word "MCM" stand for?

See above … "thousand circular mills"

4. What type of conductors is ACSR-795MCM equivalent to?

In raw cross sectional area, 795 kcmil conductor would be equivalent to 380 mm². However, as you are asking about ACSR conductors, there is more to the story on equivalency … these conductors will be build of "X" strands of aluminum conductor and "Y" strands of steel for strength, indicated as "X/Y". Common 795 kcmil conductor constructions include the following stranding: 36/1, 24/7, 45/7, 54/7, and 30/19. Each of these constructions have slightly different resistance and reactances, but significantly different mechanical strengths and costs.