External Setpoint - Grundfos E Serie Instrucciones De Instalación Y Funcionamiento

The table below shows the suggested controller settings:
System/application
Heating
system
p
L [m]
1
p
p
Q
0,5
t
L [m]
2
t
L [m]
2
L [m]
2
0,5
t
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
How to set the PI controller
For most applications, the factory setting of the controller
constants Kp and Ti will ensure optimum pump operation.
However, in some applications an adjustment of the controller
may be needed.
Proceed as follows:
1. Increase the gain (Kp) 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 (Kp) 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 (Ti) until the motor becomes
unstable.
4. Set the integral time (Ti) to twice the value which made the
motor unstable. This is the correct setting of the integral time.
Kp
Ti
Cooling
1) 2)
system
0,5 0,5
L < 5 m: 0,5
1
0,5 L > 5 m: 3
1
L > 10 m: 5
1
0,5 0,5
0,5 0,5
- 0,5 10 + 5L
2
0,5 10 + 5L
2
- 0,5 30 + 5L
2
General rules of thumb:
• If the controller is too slow-reacting, increase Kp.
• If the controller is hunting or unstable, dampen the system by
reducing Kp or increasing Ti.

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 section 12. External setpoint
8.3.4 Signal relay
Pumps up to 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 operating situation
the signal relay should be activated.
Up to 7.5 kW
• Ready
• Fault
• Operation
• Pump running (only three-phase pumps up to 7.5 kW)
• Warning (only three-phase pumps up to 7.5 kW).
11-22 kW
• Ready
• Alarm
• Operation
• Pump running
• Warning
• Relubricate.
Fault and alarm cover faults resulting in alarm.
Warning covers faults resulting in warning.
relubricate covers only that one individual event. For
Note
distinction between alarm and warning, see section
8.1.3 Fault indications.
For further information, see section
relay.
signal.
11-22 kW
• Ready
• Alarm
• Operation
• Pump running
• Warning
• Relubricate.
15. Indicator lights and signal
21