Grundfos CRE Series Installation And Operating Instruction page 37

H
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
p
Controller settings
For recommended controller settings, see the section on the
controller.
Related information
10.15 Controller (Controller settings)
10.50 Assisted pump setup
10.5.3 Constant temperature
This control mode ensures a constant temperature. Constant
temperature is a comfort control mode that you can use in domestic
hot-water systems to control the flow to maintain a constant
temperature in the system.
H
Constant temperature
This control mode requires either an internal or external
temperature sensor as shown in the examples below.
Example:
• One external temperature sensor
Q
t
Q
t
t
Controller settings
For the recommended controller settings, see the section on the
controller.
Related information
10.15 Controller (Controller settings)
10.5.4 Constant differential pressure
The pump maintains a constant differential pressure, independently
of the flow rate in the system. This control mode is primarily suitable
for systems with relatively small pressure losses.
H
Constant differential pressure
The setting range is between 12.5 % and 100 % of maximum head.
This control mode requires either an internal or external differential-
pressure sensor or two external pressure sensors as shown in the
examples below.
Examples:
• Factory-fitted differential-pressure sensor.
p
• One external differential-pressure sensor.
The pump uses the input from the sensor to control the
differential pressure.
You can set the sensor manually or by using the Assist menu.
See the section on assisted pump setup.
• Two external pressure sensors.
Q
p
p
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