Grundfos CRE Notice D'installation Et De Fonctionnement page 36

7.4.3 "Constant differential pressure"
Pump variant
CME
CRE, CRIE, CRNE, CRKE, SPKE, MTRE
The pump maintains a constant differential pressure,
independently of the flow in the system. See fig. 44.
H
Fig. 44 "Constant differential pressure"
This control mode requires either a differential-pressure sensor or
two external pressure sensors. See the examples below:
Examples
• One 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 section 7.41 "Assisted pump
p
• Two pressure sensors.
Constant differential-pressure control is achievable with two
pressure sensors. The pump uses the inputs from the two
sensors and calculates the differential pressure.
Both 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 section
7.41 "Assisted pump setup".
p
p p
Fig. 45 "Constant differential pressure"
"Controller settings"
For recommended controller settings, see section
Controller settings"
7.11 "Controller" ("
Factory setting
See section 10. Technical data.
36
"Constant
differential
pressure"
●
●
Q
setup".
p
p
p
p
).
7.4.4 "Constant differential temperature"
Pump variant
CME
CRE, CRIE, CRNE, CRKE, SPKE, MTRE
The pump maintains a constant differential temperature in the
system and the pump performance is controlled according to this.
See fig. 46.
H
△t
Fig. 46 "Constant differential temperature"
This control mode requires either two temperature sensors or one
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/Pt1000 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 section 7.41 "Assisted pump
Examples
• One differential-temperature sensor.
The pump uses the input from the sensor to control the
differential temperature.
You can set the sensor manually or by using the "Assist"
menu. See section 7.41 "Assisted pump
t
• Two temperature sensors.
Constant differential-temperature control is achievable with
two temperature sensors. The pump uses the input from the
two sensors and calculates the differential temperature.
Both sensors must have the same unit and must be set as
feedback sensors. You can do this manually, sensor by
sensor, or by using the "Assist" menu. See section
7.41 "Assisted pump setup".
t
t
t
Fig. 47 Constant differential temperature
"Controller settings"
For recommended controller settings, see section
Controller settings"
7.11 "Controller" ("
Factory setting
See section 10. Technical data.
"Constant
differential
temperature"
●
●
Q
setup".
setup".
).