15
Setting the PI controller:
For most applications, the factory setting of the controller
constants K
p
and T
i
will ensure optimum pump operation. In the
following cases, a change of the setting can be useful or
necessary.
A change of the T
i
setting can be useful:
• in a differential-pressure control system if the sensor is placed
far away from the pump.
A change of the T
i
setting, and in some cases the K
p
setting, may
be necessary:
• if the pump is controlled on the basis of temperature or
differential temperature.
The table below shows the recommended controller settings:
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.
6.3.3 Selection of external setpoint signal
The input for external setpoint signal can be set to different signal
types.
Select one of the following types:
•
0-5 V (t
hree-phase pumps, 11-22 kW,
only),
•
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.
The setpoint set is the maximum value of the external setpoint
signal, section
The actual value of the
external setpoint can be read from section
6.3.4 Selection of fault, operating or ready signal relay
It can be selected in which situation the relay should be activated:
•
Fault
(fault indication),
•
Operation (operating indication)
,
•
Ready (ready indication)
.
See section
11. Indicator lights and signal relay.
6.3.5 Blocking of the buttons on the pump
The buttons
and on the pump can be set to:
•
Active,
•
Not active.
6.3.6 Allocation of pump number
A number between 1 and 64 can be allocated to the pump. In the
case of bus communication, a number must be allocated to each
pump.
System/
application
K
p
T
i
Heating
system
1)
Cooling
system
2)
0.5
0.5
0.5
L < 5 m:
0.5
L > 5 m: 3
L > 10 m: 5
0.5
0.5
0.5
0.5
0.5
–0.5
10 + 5L
0.5
10 + 5L
0.5
–0.5
30 + 5L
Δ
p
L [m]
Δ
p
p
Q
L [m]
t
L [m]
Δ
t
L [m]
t
Grundfos.bk Page 15 Tuesday, April 17, 2007 8:54 AM
