Grundfos CRE - Operating Range

L2: distance in meters between heat exchanger and sensor.
Constant differential
temperature
K
p
T
i
t
L2
-0.5 10 + 5L2
t
t
t
L2
L2: Distance [m] between heat exchanger and sensor.
Constant flow rate
K
p
T
i
Q
0.5 0.5
Constant pressure
K
p
T
i
p
0.5 0.5
p
0.5 0.5
Constant level
K
p
T
i
L
-20 0
L
20 0
General rules of thumb
If the controller is too slow-reacting, increase the gain.
If the controller is hunting or unstable, dampen the system by
reducing the gain or increasing the integral time.
Factory setting
See the section on factory settings.
Related information
9.2 Factory settings
8.12
"Operating range"
Pump variant "Operating range"
CME ●
CRE, CRIE, CRNE, CRKE, SPKE,
MTRE
●
Set the operating range as follows:
• Set the minimum speed within the range from fixed minimum
speed to user-set maximum speed.
• Set the maximum speed within the range from user-set
minimum speed to fixed maximum speed.
The range between the user-set minimum and maximum speeds is
the operating range. See the figure below.
1
2
3
4
5
100%
67%
24%
13%
0%
TM006785
Example of minimum and maximum settings
Pos. Description
1 Fixed maximum speed
2 User-set maximum speed
3 Operating range
4 User-set minimum speed
5 Fixed minimum speed
Factory setting
See the section on factory settings.
Related information
9.2 Factory settings
44
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