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#### BPC\$

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I gotta motor that is three phase. I just wanna know what the 208-230v means? I understand the hi and low voltages but on the low voltages can both 208v and 230v work on it?

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#### bkmichael65

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I gotta motor that is three phase. I just wanna know what the 208-230v means? I understand the hi and low voltages but on the low voltages can both 208v and 230v work on it?

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Exactly. It's rated to run on low voltage wiring at either 208 or 230

#### BPC\$

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Ok awesome thanks alot buddy

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#### JRaef

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There is a great piece of literature called the "Cowern papers" originally published by Baldor (where Cowern worked at the time). Unfortunately since ABB bought Baldor, this information seems to have vanished from their site, or at least it is no longer as easy to find. But fortunately a number of Baldor distributors have recreated it.
http://www.motorsanddrives.com/cowern/motorterms11.html

Here is an excerpt from that regarding this issue, I think it's one of the best explanations:

So most motor manufacturers have taken a different approach to handling these smaller motors. This approach is that by using a somewhat more conservative design on the 230 volt motors it is possible to create a 3 phase, tri-voltage motor with voltage ratings of 208-230/460. With this approach the 230 volt winding (and connection diagram) is used on the 208 volt power system. When this approach is taken the motor manufacturer is essentially saying that this motor can be successfully operated on voltages as low as 208 minus 10% or 187 volts. This approach usually works very well since 208 volt power systems are normally used in small buildings with relatively short distances between the incoming power service and the utilization equipment. These short runs tend to make 208 volt power systems quite stable so that the limit of the motor’s low voltage capability is seldom tested.
On motors larger than 10 HP the 200 volt motor is generally the best choice, but in many situations 230 volt motors are frequently and successfully applied on the 208 volt systems. In some cases a derate table is provided for the “low voltage” situation. In other cases the motor service factor may be reduced from 1.15 down to 1.0 when it is applied to a 208 volt power system.

micromind and 8V71
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