Current Calculation Question

[hanksmith]

Should be simple but I am not thinking quite right this morning.

If I am given a load and being told it requires 500kW how do I calulate the current it will draw? The load is for a large machine and will be mainly motor loads.

Would I take the 500kw divide it by the voltage * 1.73 * PF

Or do I ignore power factor and just take the 500kw and divide it by the voltage * 1.73

Thanks
Hank

 

[rbulsara]

With the PF and the voltage is line to line. Do not forget to multiply kW by 1000 to get W (or use voltage in kV).

I presume this is a 3 phase calculation.

Rafiq Bulsara

http://www.srengineersct.com

 

[MikiBg]

You can't ignore PF because it is active power. Motor rated power is mechanical (shaft power) by default and that means you have to assume some efficiency as well: I=mech.power/(eff*sqrt(3)*line voltage*pf).
If your data assumes electrical power, then: I=el.power/(sqrt(3)*line voltage*pf)