Grundfos CRE Series Installation And Operating Instruction page 38

Constant differential-pressure control is achievable with two
individual pressure sensors. The pump uses the inputs from the
two sensors and calculates the differential pressure.
The sensors must have the same unit and must be set as
feedback sensors. You can set the sensors manually, sensor by
sensor, or by using the Assist menu. See the section on
assisted pump setup.
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Controller settings
For recommended controller settings, see the section on the
controller.
Related information
10.15 Controller (Controller settings)
10.50 Assisted pump setup
10.5.5 Constant differential temperature
The pump maintains a constant differential temperature in the
system and the pump performance is controlled according to this.
H
Constant differential temperature
This control mode requires either two temperature sensors or one
external differential-temperature sensor. See the examples below.
The temperature sensors can either be analog sensors connected
to two of the analog inputs or two Pt100/1000 sensors connected to
the Pt100/1000 inputs, if these are available on the specific pump.
Set the sensor in the Assist menu under Assisted pump setup.
See the section on assisted pump setup.
Examples:
• Two external temperature sensors.
Constant differential-temperature control is achievable with two
temperature sensors. The pump uses the inputs from the two
sensors and calculates the differential temperature.
The sensors must have the same unit and must be set as
feedback sensors. You can set the sensors manually, sensor by
sensor, or by using the Assist menu. See the section on
assisted pump setup.
• One external differential-temperature sensor.
The pump uses the input from the sensor to control the
differential temperature.
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You can set the sensor manually or by using the Assist menu.
See the section on assisted pump setup.
Controller settings
For recommended controller settings, see the section on the
controller.
Related information
10.15 Controller (Controller settings)
10.50 Assisted pump setup
10.5.6 Constant flow rate
The pump maintains a constant flow in the system, independently of
the head.
H
Constant flow rate
This control mode requires an external flow sensor. See the
example below.
Example:
• One external flow sensor.
Constant flow rate
Controller settings
For recommended controller settings, see the section on the
controller.
Related information
10.15 Controller (Controller settings)
10.5.7 Constant level
The pump maintains a constant level, independently of the flow
rate.
H
Constant level
This control mode requires an external level sensor.
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set
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