What Is the Correct Current Draw Calculation for a 2Hp 208V 3-Phase Motor?

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SUMMARY

The correct current draw calculation for a 2 Hp 208V 3-phase motor with a unity power factor and 100% efficiency is approximately 7.17 Amps per phase. The formula used is P(watts) = I(Amps) * V(volts), where the total power of 1492 watts is divided by the square root of 3 (1.73) to account for the three-phase system. Therefore, the calculation for current draw in a three-phase system is I = P / (V * √3), leading to a more accurate current draw of about 4.14 A per phase when properly calculated.

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  • Understanding of three-phase electrical systems
  • Familiarity with power factor concepts
  • Basic knowledge of electrical formulas (P=IV)
  • Ability to perform calculations involving square roots
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Matt1234
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hi there,
Looking for some info, on how i would find the current draw of a 2 Hp motor running at 208v 3 phase with a unity power factor and efficenty of 100%. I can't seem to put it together today and cannot get ahold of a TA, basically i need to size wires/fuses in a schematic for this current draw and completely forgot how to do this. I keep getting 862 A which i know is way too high. I know 2 hp = 1492 watts. Can someone please help me with the mathematic breakdown? Would be appreciated.


i think I am losing it been a real bad week for me.
I think can use this:

P(watts) = I(Amps) * v(volts)

1492 = I * 208
I = 7.17 A per phase?

Is this correct?


Thanks,
Matt.
 
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Anyone?
 
This is not my field of expertise, but I am wondering if the 1492 W is the total power, and should be divided up among the 3 phases before doing the "P=IV" calculation?
 
Your calculation is correct for a single phase motor. For three phase you need to divied by 1.73 (square root of 3).
 

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