Fire pump kW to kVA

[kwired]

Power IS power. That's it. Whether it is HP or kW. What you do with that power is your choice. For me and the vast majority of the world we use kW.

True. but with a motor you have input power that is higher than output power.
NEMA motors are marked in HP, that is the rated output power. They are also marked in amps, but that is what you get for input amps after factoring in efficiency and power factor on the input @ nameplate volts.

 

[Besoeker3]

True. but with a motor you have input power that is higher than output power.
NEMA motors are marked in HP, that is the rated output power. They are also marked in amps, but that is what you get for input amps after factoring in efficiency and power factor on the input @ nameplate volts.

Yes, obviously. We just don't use HP. Don't reed to use HP might be a better way of saying it.

 

[David Castor]

Power IS power

No one is saying otherwise. But because of power losses, there are more electrical kW going into the motor than mechanical kW at the motor shaft.

 

[Besoeker3]

No one is saying otherwise. But because of power losses, there are more electrical kW going into the motor than mechanical kW at the motor shaft.

It's still kW at the motor shaft.

 

[xptpcrewx]

343x.208x1.733=123.57kVA.

This is correct for what you are trying to do since no motor is 100% efficient.

 

[Besoeker3]

This is correct for what you are trying to do since no motor is 100% efficient.

I don't think anyone here would remotely consider that a motor would be 100% efficient.

 

[xptpcrewx]

I don't think anyone here would remotely consider that a motor would be 100% efficient.

Yet that’s exactly what the OP did in his second calculation.

 

[Besoeker3]

Yet that’s exactly what the OP did in his second calculation.

Then it shouldn't be correct if that's we did.