Where is the pump energy lost in a central chilled water system with a pump efficiency of say 85% & motor efficiency of 95%?

Can you elaborate more what types of losses you are talking about?

Please I need more description of the question because I am unable to understand the required

Hi, I am referring to total power input to the pump motor.
Whether it is3 way valve or2 way valve application & pump sizing has been done as per the industry norms please analyse on the total power input to the pump motors.
Indicated efficiencies are for guidelines and consider them for analysis purposes only.
I am looking for break down on energy lost to different media.
Mr Adrian must have not understood the question properly.
 

Pump energy in Central plant is lost due to many reasons.
1. 
    In Case of primary only constant flow system with3-way valve, when AHU and FCU’s (load side) are not producing any cooling effect3-way valve will bypass the chilled water without producing any cooling effect.
Due to this huge pumping energy is lost.
2. 
    If Chilled water pie sizing is not done correctly it will lead to huge pressure drops and intern pumping power is lost.
 3. 
    If the Chiller Evaporator, chilled water coil and Valve selection is not done according to the lowest pressure drop possible, it will cause pump power loss...

efficiency in engg. is described as output / input or useful energy / input energy. For pumps, the output is the work done on the liquid called WHP-water horsepower divided by the energy input to drive the pump which is the BHP-brake horsepower or the shaft power torque. 

 

And for the motor the output is the shaft power or the torque of the shaft and when a pulley is attached the BHP, and the input is the EHP, electrical horsepower which is volts and the running amps measured by an ammeter.

The pump energy lost in the chiller( chiller staging) should be compensated by running a standy by chiller, such that the supply flow should be equal or greater than the return to the chiller at any time that is where the standby pump is started to allow more flow to meet the demand, excess flow from the supply is bypassed to the return to the chiller. there is no such thing as pump energy losses in a CHW system, but a staging of the chillers to balance the supply and demand flow.