Wilo STRATOS GIGA, Installation And Operating Instructions Manual, Page: 112 / 265

English
112 WILO SE 03/2018
NOTICE:
Alternatively, constant speed (Fig. 44) or PID operating mode can also
be set.
Constant speed:
“Constant speed” mode deactivates all other control modes. The
speed of the pump is kept to a constant value and set using the rotary
knob.
The speed range is dependent on the motor and pump type.
PID-Control:
The PID controller in the pump is a standard PID controller, as
described in control technology literature. The controller compares a
measured process value to a predefined setpoint and attempts to
adjust the process value to match the setpoint as closely as possible.
Provided appropriate sensors are used, a variety of control systems
(including pressure, differential pressure, temperature and flow con-
trol) can be realised. When selecting a sensor, pay attention to the
electrical values in Table 4 „Connection terminal assignment“ on
page 93.
The control behaviour can be optimised by adjusting the P, I and D
parameters. The P (or proportional) term of the controller contributes
a linear gain of the deviation between the process (actual) value and
the setpoint to the controller output. The sign of the P term deter-
mines the controller’s direction of action.
The I (or integral) term of the controller provides integral control
based on the system deviation. A constant deviation results in a linear
increase at the controller output. Hence a continuous system devia-
tion is avoided.
The D (or derivative) term of the controller responds directly to the
rate of change of the system deviation. This affects the rate at which
the system responds. In the factory settings, the D term is set to zero,
since this is an appropriate setting for a number of applications.
These parameters should only be changed in small increments, and
the effects on the system should be monitored continuously. Param-
eter values should only be tuned by someone with training in control
technology.
Table 9: PID parameter
The direction of action of the controller is determined by the sign of
the P term.
Positive PID-Control (default):
If the sign of the P term is positive and the process value drops below
the setpoint, the control will increase the pump speed until the set-
point has been reached.
Fig. 44: Constant speed
Q
H
H
Q
n
min
n
m a x
s
H
s
Controller
term Factory
setting Setting range Increment
P 0.5 -30.0 ...-2.0
-1.99 ...-0.01
0.00 ...1.99
2.0 ...30.0 0.1
0.01
0.01
0.1
I 0.5 s 10 ms... 990 ms
1 s... 300 s 10 ms
1 s
D 0 s
(=
deactivated) 0 ms... 990 ms
1 s... 300 s 10 ms
1 s