Metric Motors vs. NEMA Motors?

[ThePunisher]

I have a vendor supplied equipment datasheet specifying the associated motor as C.V. and it is termed as "cheval vapeur".

I checked online unit conversion and 1 C.V. = 0.9852325737 Electric HP.

Is a motor with a unit of C.V. considered a metric motor?

If I were to consider an equivalent NEMA standard motor size, I will convert the c.v. to electric HP and select a NEMA standard motor. For example, a 220 c.v. will be compatible with 250HP NEMA motor.

I am doing a load calculation using NEMA motor size, or can I just take 220 c.v. instead or 250HP?

Your comments and experience is highly appreciated.

 

[electricpete]

Literally tranlsated it means "horse vapor".
I doubt that will help, but I thought it was mildly amusing

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[ScottyUK]

C.V. is a term commonly used by the European automotive industry, presumably because it allows the spec-writers to publish a numerically higher (and therefore better!) power value than using kW or HP.

I think C.V. dates back to the days of steam, hence 'vapeur'. I'm surprised to find a serious European motor manufacturer listing power ratings in anything other than kW, and I did stumble across one rated in C.V. I would assume it was a piece of crap.


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[jraef]

Or assume it is worth "horse vapors"?

I have seen this on old motors and old data sheets, particularly from the French (who like to use their own terms for things, I think just to thumb their noses at the English). I generally have considered CV to be HP, the difference is not much to be concerned with in the overall scheme of sizing motors. So 220CV would be 220HP, but you can't buy that motor, so a 250HP is the ticket.


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[DickDV]

Outside of NEMA, the concept of service factor or extra cooling capacity is largely unknown. So, when evaluating metric or non-NEMA motors, they should all be considered as service factor 1.0 unless specifically stated otherwise.

 

[electricpete]

"Must have been the beef-a-rino!"
(Kramer's reaction to the flatulent horse while giving Susan's parents a buggy ride.... Seinfeld episode 121 1/4/96)

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[peebee]

Wikipedia has an interesting article on "horsepower", there's way more definitions for horsepower than I would have ever guessed. CV is defined in there -- it is not a metric unit, it is an obsolete French unit previously used in automotive marketing.

http://en.wikipedia.org/wiki/Horsepower

 

[peebee]

Actually, taking another look at that Wikipedia article, 1CV ~= 1 metric horsepower.

 

[jraef]

So then 1 c.v. = approx. 2.3 cans of beef-a-rino




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[Skogsgurra]

If you think about it, the translations is not 'Horse Vapor' but rather 'Steam Horse (power)', which just indicates that it is the power that a steam engine can produce and that equals the power a horse can produce.

There is no difference between a European HP and a CV. The definition was taken over from James Watt and the unit was simply given a French name. It is exactly the same situation that you have in Germany, where one HP equals one PS (Pferde Sterke or Horse Strength)

Car manufacturers used to have another definition where 1 CV was equal to around 7 HP (not verified, but think I remember that from my French years). The reason seems to be fiscal, lower CV number - lower tax on the car - hence the well-known Citroën 2 CV.

Gunnar Englund

http://www.gke.org

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