Grundfos TPE2 Notice D'installation Et De Fonctionnement page 44

Guidelines for setting of PI controller
The tables below show the recommended controller settings:
"Differential-pressure
control"
p
p
p p
L1
L1
L1 = Distance ft (m) between pump and sensor.
"Temperature
Heating
control"
system
0.5
t
L2
L2
0.5
t
1)
In heating systems, an increase in pump performance results
in a rise in temperature at the sensor.
2)
In cooling systems, an increase in pump performance results
in a drop in temperature at the sensor.
L2: distance in ft (m) between heat exchanger and sensor.
"Differential-temperature
control"
t
L2
t
t
t
L2
L2: distance in ft (m) between heat exchanger and sensor.
44
K T
p i
0.5 0.5
L1 < 16.4 ft (5 m): 0.5
0.5 L1 > 16.4 ft (5 m): 3
L1 > 32.8 ft (10 m): 5
K
p
T
Cooling
i
1) 2)
system
-0.5 10 + 5L2
-0.5 30 + 5L2
K T
p i
-0.5 10 + 5L2
"Flow control"
Q
"Constant-pressure
control"
p
p
"Level control"
L
L
Rules of thumb
If the controller is too slow-reacting, increase the gain.
If the controller is hunting or unstable, dampen the system by
reducing the gain or increasing the integral time.
Factory setting
See section 35. Factory settings.
K T
p i
0.5 0.5
K T
p i
0.5 0.5
0.1 0.5
K T
p i
-2.5 100
2.5 100