How to work out 3 phase Watts

[2396help]

Hi, im doing my 2396 and there are 2 circuits in the drawings that dont have exact amps or Watts to use for calculations, all that is given is that a 16A and a 45A supply is needed, ive done all circuit calculations fine but the spreadsheet i have made up for quick reference i have included power in Watts but im struggling to get my head around it

Would for the 16A just be ohms law of P=16x230 = 3680W or would there be more to it than that

I may just be having a blond moment

Thanks

 

[kyle12111994]

Firstly, that's not Ohm's Law, Ohm's Law is Current, Voltage and Resistance.
Secondly, by doing that calculation you are calculating he power of a single phase, except you should have multiplied it by the Power Factor as well. For Three Phase power there are two calculations. Using the line to line voltage - W=√3×PF×I×V and using the line to neutral voltage - W=3×PF×I×V