Grundfos CUE Series Installation And Operating Instructions Manual page 24

10.7.2 Controller (3.2)
The CUE has a factory setting of gain (K
However, if the factory setting is not the optimum setting, the gain
and the integral time can be changed in the display.
• The gain (K ) can be set within the range from 0.1 to 20.
p
• The integral time (T ) can be set within the range from 0.1 to
i
3600 s. If 3600 s is selected, the controller will function as a P
controller.
• Furthermore, it is possible to set the controller to inverse
control, meaning that if the setpoint is increased, the speed
will be reduced. In the case of inverse control, the gain (K
must be set within the range from –0.1 to –20.
The table below shows the suggested controller settings:
24
) and integral time (T ).
p i
)
p
System/application
Heating
system
CUE
p
SP, SP-G, SP-NE: 0.5
CUE
p
SP, SP-G, SP-NE: 0.5
CUE
Q
CUE
L
CUE
0.5
t
L
2
CUE
Δt
L
2
t
CUE
L
2
0.5
CUE
Δp
CUE
L
1
Δp
* Ti = 100 seconds (factory setting).
1. Heating systems are systems in which an increase in pump
performance will result in a rise in temperature at the sensor.
2. Cooling systems are systems in which an increase in pump
performance will result in a drop in temperature at the sensor.
L = Distance in [m] between pump and sensor.
1
L = Distance in [m] between heat exchanger and sensor.
2
K
p
T
i
Cooling
1) 2)
system
0.2 0.5
0.5
0.2 0.5
0.5
0.2 0.5
–2.5 100
–0.5 10 + 5L
2
0.5 10 + 5L
2
–0.5 30 + 5L
2
0.5 0.5 *
L < 5 m: 0.5 *
1
0.5 L > 5 m: 3 *
1
L > 10 m: 5 *
1
*