[EnergyPlus_Support] RE: Cubic Curve in variable speed pump

[<adrianchong85@xxxxxxxxx>]

Jim,
Thanks for the insights. They are definitely informative especially for a new user to EPlus such as myself. 
However, out of curiosity, If you were to derive these pump coefficients, how would you go about doing this? Would it be like how I have mentioned earlier whereby we assume a constant head or rather the rated head of the pump and based on that, obtain the various pump brake horsepower and flow rate from pump performance curves usually provided by manufacturers.
sorry if I sound very inexperienced but you mentioned both pump and VSD data, what do you mean by VSD data shouldn't VSD efficiencies be accounted for in the pump curves provided by manufacturers?
On a side note, I was looking through the Eplus Engineering reference and came across the following which is part of the pseudo code for pump:variable speed 
Power = FracFullLoadPower * PumpEquip(PumpNum)%NomPowerUse 

ShaftPower = Power * PumpEquip(PumpNum)%MotorEffic