Setting The Control Mode - salmson LRE Serie Manual De Instalación Y Puesta En Servicio

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9.4

Setting the control mode

H
H
max
H
1
s
s
H
2 s
H
min
H
H
H
max
H
1
s
H
2
s
H
min
Fig. 36: Δp-c/Δp-v control
H
H
n
max
H
s
s
n
min
Fig. 37: Manual control mode
83
Δp-c/Δp-v control:
Setting (Fig. 36) Δp-c
Duty point on
1
maximum pump
curve
Duty point
2
Q
within the con-
trol range
Setting range
Q
Q
NOTE:
Alternatively, manual control mode (Fig. 37) or PID operating mode
can also be set.
Manual control mode:
"Manual control" 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.
PID controller
Q
Q
The PID controller in the pump is a standard PID controller, as
described in control engineering 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, keep in mind the elec-
trical values presented in the table titled "Connection terminal
allocation" on page 66.
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 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.
Δp-v
Starting at the duty Starting at the duty
point, draw towards the point, draw towards the
left. Read off setpoint left. Read off setpoint
H and set the pump to H
S S
this value. this value.
Starting at the duty Move to max. pump
point, draw towards the curve along control
left. Read off setpoint curve, then horizontally
H and set the pump to to the left, read off set-
S
this value. point H
pump to this value.
H , H H
min max min
see pump curves see pump curves
(in catalogue, select or (in catalogue, select or
online) online)
Pompes Salmson 04/2011
and set the pump to
and set the
S
, H
max