Dutypoint VT Booster Set, O & M Manual

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English (GB)
20
7.11 Controller (
Controller settings
)
The pumps have a factory default setting of gain (K
p
) and integral
time (T
i
).
However, if the factory setting is not the optimum setting, you can
change the gain and the integral time:
• Set the gain (K
p
) within the range from 0.1 to 20.
• Set the integral-action time (T
i
) within the range from 0.1 to
3600 s.
If you select 3600 s is, the controller will function as a P
controller.
Furthermore, you can set the controller to inverse control.
This means that if you increase the setpoint, the speed will be
reduced. In the case of inverse control, you must set the gain (K
p
)
within the range from -0.1 to -20.
Guidelines for setting of PI controller
The tables below show the recommended controller settings:
L1 = Distance [m] between pump and sensor.
1)
In heating systems, an increase in pump performance will
result in a rise in temperature at the sensor.
2)
In cooling systems, an increase in pump performance will
result in a drop in temperature at the sensor.
L2 = Distance [m] between heat exchanger and sensor.
L2 = Distance [m] between heat exchanger and sensor.
General rules of thumb
If the controller is too slow-reacting, increase K
p
.
If the controller is hunting or unstable, dampen the system by
reducing K
p
or increasing T
i
.
Factory setting
See section
16. Factory settings
.
Pump variant
Controller
(Controller settings)
CME ●
CRE, CRIE, CRNE, SPKE, MTRE ●
Constant differential
pressure
K
p
T
i
0.5 0.5
0.5
L1 < 5 m: 0.5
L1 > 5 m: 3
L1 > 10 m: 5
Constant
temperature
K
p
T
i Heating
system
1)
Cooling
system
2)
0.5 -0.5 10 + 5L2
0.5 -0.5 30 + 5L2
p
p
p p
ǻS
L1
L1
ǻS
L2
t
L2
t
Constant differential
temperature
K
p
T
i
-0.5 10 + 5L2
Constant flow rate K
p
T
i
0.5 0.5
Constant pressure K
p
T
i
0.5 0.5
0.5 0.5
Constant level K
p
T
i
-2.5 100
2.5 100
t
L2
t
t
t
L2
Q
p
p
L
L