Grundfos CRE Series User Manual

9.5 Control mode
You can choose between the following control modes:
• Prop. pressure (proportional pressure)
• Const. pressure (constant pressure)
• Const. temp. (constant temperature)
• Con. diff. press. (constant differential pressure)
• Con. diff. temp. (constant differential
temperature)
• Const. flow rate (constant flow rate)
• Const. level (constant level)
• Const. other val. (constant other value)
• Const. curve (constant curve).
9.5.1 Proportional pressure
The head of the pump is reduced at decreasing water
demand and increased at rising water demand. See
the figure below.
This control mode is especially suitable in systems
with relatively large pressure losses in the distribution
pipes. The head of the pump increases proportionally
to the flow in the system to compensate for the large
pressure losses in the distribution pipes.
The setpoint can be set with an accuracy of 0.1 m.
The head against a closed valve is half the setpoint.
The setting range is between 25 % and 90 % of
maximum head.
For more information about settings, see section on
proportional-pressure setup.
H
Q
Hset
Hset
2
TM057909
Proportional pressure
Example:
• Factory-fitted differential-pressure sensor.
p
TM057880
Proportional pressure
Controller settings
For the recommended controller settings, see the
section on the controller.
Related information
9.16 Controller (Controller settings)
9.5.2 Constant pressure
We recommend this control mode if the pump is to
deliver a constant pressure, independently of the flow
in the system. The pump maintains a constant
pressure independently of the flow rate.
H
Q
TM057901
Constant pressure
This control mode requires an external pressure
sensor as shown in the examples below. You can set
the pressure sensor in the Assist menu. See the
section on assisted pump setup. The setting range is
between 12.5 % and 100 % of maximum head.
Example:
• One external pressure sensor
p
TM057881
p
TM057882
Controller settings
For recommended controller settings, see the section
on the controller.
Related information
9.16 Controller (Controller settings)
9.51 Assisted pump setup
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English (GB)

Grundfos CRE Series Specifications

General

Motor Type	Asynchronous
Enclosure Class	IP55
Insulation Class	F
Series	CRE
Protection Class	IP55
Material	Stainless Steel
Applications	Water Supply, Pressure Boosting, Irrigation
Pumped liquid	Clean liquids
Approvals	CE
Voltage	380-415V
Connection Size	DN 32 to DN 100
Efficiency	IE3 Premium Efficiency
Power Supply	3-phase
Liquid Temperature Range	-10°C to +120°C
Temperature Range	-10°C to +120°C