The situation becomes more complicated and less
efficiency if the number of chilled water pumps does
not equal the number of chillers. For example, a system
with three chillers may have two chilled water pumps,
each of which is sized for the total capacity of the plant.
In such cases, you cannot simply valve off each
evaporator as its chiller turns off. This is because you
may cause water flow rates through the evaporators of
the operating chillers that are too high or too low, as
follows.