Lauda P 10, Operation Manual

Page: 97 / 160

Only modify the control parameters if you possess adequate knowl-
edge of control system engineering.
6.8.1 Control basics
A brief explanation of terms
Actuating
signal
- Initial value of the controller to compensate for the differ-
ence between the actual value and target value (control
deviation).
PID con-
troller
- The PID controller operates with extreme speed and preci-
sion and consists of a P, I and D-component.
Proportional
range Xp
- The proportional range Xp indicates the temperature range
within which the proportional component (P-component)
of the controller represents 0 – 100 % of the maximum
actuating signal. If the preset Xp is 10 K and the control
deviation is 2 K, for example, the P-component is 20 %
of the actuating signal. If the control deviation is 10 K or
more, the P-component is 100 % of the actuating signal.
Adjustment
time Tn
- The adjustment time is crucial for the I-component of
the actuating signal. It specifies the interval at which an
existing control deviation is integrated. The higher the Tn,
the slower the control deviation is integrated and the more
sluggish the control becomes. A small Tn makes the control
more dynamic and eventually results in vibrations.
Hold-back
time Tv
- The D-component of the actuating signal is formed from
the hold-back time Tv. It influences the speed with which
the actual value approaches the target value and counter-
acts the P-component and I-component. The greater the
preset hold-back time Tv, the more intensively the output
signal is attenuated. Rule of thumb: Tv = Tn x 0.75.
Attenuation
time Td
- Attenuation time of the D-component. Rule of thumb:
Td = Tv x 0.15.
Correction
limitation
- Represents the maximum permitted deviation between the
temperature at the external consuming unit and the tem-
perature at the outlet.
One important prerequisite for an acceptable control quality is a well
designed hydraulic system. The best possible connection must therefore be
established between the temperature control application and the constant
temperature equipment.

Use short hoses with a large cross section to reduce the flow resistance.
More heat transfer liquid can circulate in a short time, resulting in a
shorter circulation time.

Select the thinnest possible heat transfer liquid with the highest possible
heating capacity. Precedence list: Water, water-glycol, oils, Fluorinert
®
.

Select the highest possible pump level.

For external applications, set the flow rate through the external con-
suming unit as high as possible.

With bath thermostats, make sure that the circulation in the bath is
adequate.
Definition
Optimizing the hydraulic system
V6 PRO bath thermostats and circulation thermostats 97 / 156