# 575v motor with usable at 208v on the nameplate.



## bcard519 (10 mo ago)

I am curious about the usable at 208V comment. If I supply the motor with a 3 phase 208v feed, it'll work?
Obviously it will draw more amps, but is that the only downside. When I look at the wiring diagram is just straight L1-T1, L2-T2, L3-T3. I know with a lot of motor with you move the "bars" around in the junction box for "high" and "low" voltage, but usually both are shown on the nameplate. 
Would the motor have the same torque etc. Its to be used in a direct drive exhaust fan.

Thanks for input, I'm very curious about this.


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## joe-nwt (Mar 28, 2019)

I think if it was usable at 208V (it won't be) it would be marked so in the empty box to the right.


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## micromind (Aug 11, 2007)

That's a Baldor (now ABB) nameplate, they all state 'useable at 208'. If it actually is ok with 208, it'll have an amp rating for 208. That motor is 575 only. 

Very misleading but they've been that way for many years.


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## emtnut (Mar 1, 2015)

Standard label lol

If it was a 230V motor, some are usable at 208V.


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## paulengr (Oct 8, 2017)

A dual voltage motor would still have T1, T2, T3 connected but depending on the design you would connect other leads or jumpers at the peckerhead. A dual voltage motor splits the coils in two so that you can them up either series or parallel. This allows for instance a 460 V motor with series coils to be configured for 230 V. As a "230 V" motor often they can actually run around 200-240 V just as the same motor might easily go down to 440 V to support "global" markets. However 575 / 2 = 287.5 V. That's not really near any particular half voltage standard anywhere so there's really no need to provide dual voltage support. The only other nominal voltage that I've ever seen 575 V motors used for is that in the American South there is a "cotton gin" voltage that is around 540-550 V. It's not popular even here but there is still equipment out there using it. We use 575 V motors since they are close enough while a 460 V motor can't be used. Other than that, 575 V motors are pretty much exclusive to Canada.


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## backstay (Feb 3, 2011)

Paper mills along the border in the US can have 575 motors. Most of the motors in International Falls were.


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## Almost Retired (Sep 14, 2021)

backstay said:


> Paper mills along the border in the US can have 575 motors. Most of the motors in International Falls were.


there is a papermill in louisiana that uses 575V motors, and not 460V


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## backstay (Feb 3, 2011)

Almost Retired said:


> there is a papermill in louisiana that uses 575V motors, and not 460V


Some of the newer stuff was 480 3 ph. And the new paper machine was fed from the utility at 14,400 volts. The rest of the mill was 6,600(steam turbines and water turbines, and utility connection)


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## JRaef (Mar 23, 2009)

joe-nwt said:


> I think if it was usable at 208V (it won't be) it would be marked so in the empty box to the right.


Yep. Its the same nameplate used for everything, so the silk screening comes with that section. If it were a 230/460V motor 9or a straight 230V), and it was OK with 208V, it would have the 208V FLA stamped into that box on the right. If that box is empty, you ignore it.


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## kb1jb1 (Nov 11, 2017)

Just a question.
If it is a 575 wye, what would be the voltage to ground?


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## emtnut (Mar 1, 2015)

kb1jb1 said:


> Just a question.
> If it is a 575 wye, what would be the voltage to ground?


347V phase to ground.
It's actually a 600V wye. 575V is the motor utilization rating (ie, 230V for 240V supply)


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## bcard519 (10 mo ago)

Definitely very misleading, this is why I was confused. Dual voltage have the voltage/amps ratings for both. I figure with the extra amps at the lower voltages the windings wouldn’t hold up over time .


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## micromind (Aug 11, 2007)

bcard519 said:


> Definitely very misleading, this is why I was confused. Dual voltage have the voltage/amps ratings for both. I figure with the extra amps at the lower voltages the windings wouldn’t hold up over time .


Each winding has the same volts and amps on it at 230 or 460. 

Often, the 208 amp rating is different though. Sometimes higher, sometimes lower, sometimes the same.


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## paulengr (Oct 8, 2017)

bcard519 said:


> Definitely very misleading, this is why I was confused. Dual voltage have the voltage/amps ratings for both. I figure with the extra amps at the lower voltages the windings wouldn’t hold up over time .


That is the correct way to determine voltage(s). It will also specify the winding info most of the time. MOST manufacturers follow NEMA and/or IEC standard wiring. Motors I work on are usually so faded I can’t even make out the silk screen stuff.


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## paulengr (Oct 8, 2017)

micromind said:


> Each winding has the same volts and amps on it at 230 or 460.
> 
> Often, the 208 amp rating is different though. Sometimes higher, sometimes lower, sometimes the same.


Amps is amps…thermally it’s all I-squared x Z. If we wire series we can only put half the Amps on it. There will be sometimes a tiny difference but it’s all round off/measurement error. The motor manufacturers “horsepower” or “kw” rating is based on the torque they guarantee as a minimum at the specified voltage. Torque increases with voltage (across each coil) so a motor that is marked say 208-230 is going to produce close to name plate at 208. You will get more at 230 so at 230 it will run lower Amos or pull more load. But it will be at least what the name plate says. You get ZERO extra at 208 though. It could be marked with the treated values at 230 but why do that.. it serves no purpose giving a lower FLA.


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