23
The table below shows the suggested controller settings:
4
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
1
= Distance in [m] between pump and sensor.
L
2
= Distance in [m] between heat exchanger and sensor.
How to set the PI controller
For most applications, the factory setting of the controller
constants K
p
and T
i
will ensure optimum pump operation.
However, in some applications an adjustment of the controller
may be needed.
Proceed as follows:
1. Increase the gain (K
p
) until the motor becomes unstable.
Instability can be seen by observing if the measured value
starts to fluctuate. Furthermore, instability is audible as the
motor starts hunting up and down.
Some systems, such as temperature controls, are slow-
reacting, meaning that it may be several minutes before the
motor becomes unstable.
2. Set the gain (K
p
) to half the value of the value which made the
motor unstable. This is the correct setting of the gain.
3. Reduce the integral time (T
i
) until the motor becomes
unstable.
4. Set the integral time (T
i
) to twice the value which made the
motor unstable. This is the correct setting of the integral time.
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
.
8.3.3 External setpoint
The input for external setpoint signal can be set to different signal
types.
Select one of the following types:
•
0-10 V
•
0-20
mA
•
4-20 mA
•
Not active
.
If
Not active
is selected, the setpoint set by means of the R100 or
on the control panel will apply.
If one of the signal types is selected, the actual setpoint is
influenced by the signal connected to the external setpoint input,
see
8.3.4 Signal relay
Pumps of 0.37-7.5 kW have one signal relay. The factory setting
of the relay will be
Fault
.
Pumps of 11-22 kW have two signal relays. Signal relay 1 is
factory set to
Alarm
and signal relay 2 to
Warning
.
In one of the displays below, select in which one of three or six
operating situations the signal relay should be activated.
For further information, see section
15. Indicator lights and signal
System/application
Kp
T
i
Heating
system
1)
Cooling
system
2)
0.5
0.5
0.5
L
1
< 5 m:
0.5
L
1
> 5 m: 3
L
1
> 10 m: 5
0.5
0.5
0.5
0.5
0.5
– 0.5
10 + 5L
2
0.5
10 + 5L
2
0.5
– 0.5
30 + 5L
2
Δ
p
L
1
[m]
Δ
p
p
Q
t
L
2
[m]
Δ
t
L
2
[m]
L
2
[m]
t
0.37-7.5 kW
•
Ready
•
Fault
•
Operation
.
11-22 kW
11-22 kW
•
Ready
•
Alarm
•
Operation
•
Pump running
•
Warning
•
Relubricate
.
•
Ready
•
Alarm
•
Operation
•
Pump running
•
Warning
•
Relubricate
.
Note
Fault and Alarm cover faults resulting in Alarm.
Warning covers faults resulting in Warning.
Relubricate covers only that one individual event.
For distinction between alarm and warning, see
section 8.1.3 Fault indications.
