ITT PumpSmart PS220, Руководство по конфигурации и эксплуатации

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PS220 Configuration & Operation Guide
PS220 170
Functions &
Features
Pressure Boost
In a constant pressure system often times the systems design pressure setpoint is set to compensate for
the maximum frictional losses at maximum flow. This practice will ensure that every user on the system re-
ceives the required pressure no matter what the flow rate. However, in times of normal or reduced capac-
ity, excess pressure is generated that provides little useful work and reduces the overall Flow Economy of
the pumps. This means that typically in a multi-pump system, excess pressure may be wasted when more
than 2 or more pumps are designed to run to satisfy system pressure requirements when only 1 may need
to run to satisfy lower demand and at a reduced speed. See the Diagram Below:
The PumpSmart PS220 can optimize a constant pressure multi-pump system by adding a “boost pressure”
to the pressure setpoint as pumps are staged on and subtracting it as pumps are staged off in these types
of systems. As each lag pump is brought online, indicating an increase in flow, PumpSmart will automat-
ically increase the pressure setpoint as set by parameters 81.02 ”VALUE DECREASE” and 81.03 “VALUE
INCREASE”.
The amount of pressure increase to the setpoint is determined by the following formula:
(1 + VALUE INCREASE – VALUE DECREASE)
EXAMPLE: In a 4-pump system the set-point is 100psi:
The VALUE INCREASE is 10%
The VALUE DECREASE is 5%.
Based on the formula the set-point increase equals = 1+0.10-0.05 = 1.05
When 2 pumps are running the pressure set-point = 100 psi x 1.05 = 105 psi.
When 3 pumps are running the pressure set-point = 105 psi x 1.05 = 110.25 psi.
When 4 pumps are running the pressure set-point = 110.25 psi x 1.05 = 115.76 psi.