Detailed Descriptions; Control Modes - Grundfos CIU 300 Functional Profile And User Manual

7. Detailed descriptions

7.1 Control modes

Control modes Description
Open loop
The setpoint of the booster system will be interpreted as setpoint
for the system performance.
Constant speed
The setpoint value is a percentage of the maximum performance
of the subpumps.
No sensor is required.
Closed loop
The setpoint of the booster system will be interpreted as setpoint
for the pressure.
Constant pressure
The controller in the booster system will change the booster speed
so that the pressure is constant, regardless of the flow.
A pressure sensor is required.
Closed loop
Constant flow, constant level, constant temperature or constant
Constant flow
percentage can be obtained by replacing the main pressure sensor
Constant level
with another sensor, e.g. a flow sensor is needed for flow control,
Constant temperature
a level sensor is needed for level control and a temperature sensor
Constant percentage
is needed for temperature control.
Constant flow is illustrated to the right.
Closed loop
The setpoint of the booster system will be interpreted as basic
setpoint for the proportional-pressure mode (the black dot in the
Proportional pressure
illustration).
A pressure sensor is required.
H = Pressure (Head)
Q = Flow
Illustration
H
Q
H
Q
H
Q
H
Q
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