see how fast you can answer

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rondal1

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with out using anything but your head. no out side help now. tell me what mcm means an were it come from? i know we all have seen it on the big rolls of the 250mcm,& bigger but what& were does it come from. remember that when you buy 250 or bigger it is always kmc, not mcm.
 
Re: see how fast you can answer

paul that is right. now wrer does the mcm come in to play? sorry for that i ment to kmc. we use kmc now, why?

[ December 19, 2005, 01:17 AM: Message edited by: rondal1 ]
 
Re: see how fast you can answer

Interesting since robjofg010q7ikp65p24thlhug1pkalnddcg(at)4ax.com...
= After that, the addition of "oughts" would become rediculous and
= confusing because eventually you would get to 10/0! So instead, the
= convention switches to using the measured cross sectional area
= expressed in Circular Mils (CM) representing 1/1000 of a circular
= inch.. 4/0 is 212kCM, so the next size manufactured beyond that is
= 250kCM, then 300, then 350, 400, 500 600 etc., and goes up to 2000kCM.
= For all practical purposes though, 750kCM is the largest used in
= common installations becuse of the stiffness, so larger ampacities are
= typically done with paralelled runs of smaller conductors. As
= mentioned by others, kCM used to be referred to as MCM, but that
= officially changed in the NEC 2 years ago.
=
man numerals end at M (1000)
 
Re: see how fast you can answer

Allen, excellent answer. But actually the MCM to kcmil conversion took place in the 1993 NEC.
 
Re: see how fast you can answer

It's tough teaching an old dog new tricks. Frankly, I don't know why the CMP made the change from MCM to KCM. When I walk into the supply houses and ask for 250 MCM they all know what I'm talking about. The same goes for BX and Roamex instead of AC cable or NMC. The supply houses know what you mean when you ask for it. To me it serves as a means of identifying newbees to the trade. It reminds me of when I first landed in Viet Nam. As a newbee I walked around the puddles in the roads. After a few months and a total attitude change I was walking right through them. If you ask for 250 MCM at the supply house no one is going to say "You mean kay cee mills don't you ?"

I wish the CMP's would stick to things that are really important to change instead of MCM to KCM. It's tough enough trying to know and understand everything in the NEC, NFPA, BOCA, building codes, energy codes, etc without trying to get everyone to use KCM instead of MCM. Next thing you know we'll be on the metric system !!!
 
Re: see how fast you can answer

Its not KCM in the NEC, its kcmil.
Next thing you know we'll be on the metric system
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Actually the change was part of the change to the metric sytem in the NEC. Note that the metric units are now first and the english units are second in the code now.
Don
 
Re: see how fast you can answer

Goldstar
The only thing that stays the same is CHANGE.
kcmil was adopted as part of the standards, it is not so hard to remember.
I have been around for awhile and I do not mind the changes, as a matter of fact, I get bored very easily and these changes keep me around ;)
 
Re: see how fast you can answer

M is easily confused with the metric system abbreviation for million. If you ask for 250MCM wire in Europe, they will probably think you want 250 million circuilar mill wire.

Try pulling that into a conduit!!
 
Re: see how fast you can answer

President Lincoln signed the bill making the metric system the official system in the U.S. in 1862 but it just never caught on. I remember a big push to make kids learn it in the mid to late 60s when I was in school. I remember the potheads being quick to answer that a kilo equalled 2.2 lbs. but beyond that it didn't seem to stick with anybody.
 
Re: see how fast you can answer

Originally posted by paul: M=1000 in Roman numerals
Click to expand...
Certainly the "M" means 1000. But do we really know whether the "M" in "MCM" came from the Roman numeral? Could it not have been from the word for "one thousand" in the French, Italian, or some other language, perhaps even Latin? Can anyone provide a reference that clearly states the source of the "M"?
 
Re: see how fast you can answer

I think Latin would be the most likely suspect, as it's more historically "universal" than the others.

When I buy things at the supply house, items priced on a "per one hundred" basis have a "C" in the unit column, and items priced by the thousand have an "M." "Hundred" and "thousand" are "centum" and "mille" in Latin. Could be just a coincidence, though. :D

[ December 19, 2005, 07:29 PM: Message edited by: jeff43222 ]
 
Re: see how fast you can answer

Originally posted by charlie b:
Originally posted by paul: M=1000 in Roman numerals
Click to expand...
Certainly the "M" means 1000. But do we really know whether the "M" in "MCM" came from the Roman numeral? Could it not have been from the word for "one thousand" in the French, Italian, or some other language, perhaps even Latin? Can anyone provide a reference that clearly states the source of the "M"?
Click to expand...
History tells us that the official language of the Roman Empire was Latin. The Roman Numeral M comes from the Latin word 'Mille', which means 1000. French, Italian & Spanish are all decendants from the Latin language.
 
Re: see how fast you can answer

I'm making light of this because I think it's really funny. We all know that MCM means (or has always meant) "thousand circular mils" but so does kcmils so why make the change ? So everyone will better understand ? If the CMP's are trying to move the industry over to the metric system they will fail. Standard measurements and terms are so ingrained into American culture that making a change would take centuries and for no good purpose.

Pierre, you can't possibly be bored working in NYC. They have their own electrical code above and beyond the NEC. That alone should keep you active. When I left there in 1989 I was familiar with Local Law #5, fire codes, The Board of Standards and Appeals rules & regulations and so much more. I was totally exhausted at the end of the day.

I know kcmils isn't difficult to remember but MCM is much easier to say and it won't stop there. Next thing you know we'll be changing conduit sizes, junction box sizes, fittings, devices, receptacles and who knows what else. Why ??? Take a look at the number of posts in this forum with respect to the NEC. Obviously none of us are total experts on every aspect of this code and as such we ask a lot of questions and give opinions.

My opinion - the day I go into a supply house and they don't know what I mean when I ask for 250 MCM - that's the day I put my tools on the shelf and go work for Big Orange. I'm sure I can give more credible advice that what I've overheard in recent days.

Phil,
Gold Star Electric,
New Jersey
 
Re: see how fast you can answer

Phil I bet it was just a change in language did you know that in the 1700`s German was almost voted in as the official language ;) So what would mcm or kcml be then :confused:
 
Re: see how fast you can answer

Originally posted by allenwayne:. . . did you know that in the 1700`s German was almost voted in as the official language. So what would mcm or kcml be then
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I heard we wound up with English by only one vote.

I have a source that tells me the answer to your question is, "Tausend Rundschreiben mils."
 
Re: see how fast you can answer

Originally posted by goldstar: I know kcmils isn't difficult to remember but MCM is much easier to say and it won't stop there.
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That reminds me of an observation by one of my favorite authors, Douglas Adams (rest his soul). He pointed out that it was a waste of time to describe a web site by saying (out loud), the "WWW." Each time you pronounce the letter "W," it takes you three syllables to say it. So "WWW" takes nine syllables to pronounce. If we just said "World Wide Web," we could get the job done with only three syllables.

Think it will catch on? :D
 
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