In this case shown, the I part is set too large (parameter Tn too
small). The I part integrates the control deviation until this becomes
0. If this integration runs too quickly, the control value, i.e. the
output signal of the controller, is too large. This results in (dimin-
ishing) oscillations of the actual value around the setpoint. Param-
eter Tv should be adjusted again using the formula: Tv = Tn x 0.75.
The actual value increases relatively steeply after specification of
the setpoint. The proportional range appears to be well-adjusted.
The approach to the setpoint becomes significantly slower for
diminishing control deviation. The strong reduction of the propor-
tional part (P part) must be compensated for by the integration part
(I part). In this case, the I part integrates too slowly. The parameter
Tn which specifies the integration interval must be reduced. The
lead time (parameter Tv) should also be adjusted using the fol-
lowing formula: Tv = Tn x 0.75.
6.11.2
Calling the control menu
Personnel:
n
Operating personnel
1.
Change to the main menu.
2.
Select the menu item
Setup
Control
.
Fig. 38: Control parameters Tn and Tv
too small
Fig. 39: Control parameters Tn and Tv
too large
Operation
Variocool
60
Summary of Contents for VC 1200
Page 47: ...Fig 13 Menu structure part 1 Operation Variocool 47...
Page 48: ...Fig 14 Menu structure part 2 Menu structure for Graph Clock and Standby Operation Variocool 48...
Page 103: ...General Variocool 103...
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