West Control Solutions N8800 - Manual (Page 50)

Parameters to be adjusted: E.H2O: minimum temperature for water cooling
( PArA / Cntr) t.on: pulse duration water cooling
t.off: minimum pause water cooling
4.4.3 Switching attitude non-linear ( CyCl= 2 )
With this method, the cooling power
is normally much higher than the
heating power, i.e. the effect on the
behaviour during transition from
heating to cooling may be negative.
The cooling curve ensures that the
control intervention with 0 to -70%
correcting variable is very weak.
Moreover, the correcting variable increases very quickly to max. possible
cooling. Parameter F.H2O can be used for changing the characteristic curve. The
standard method (see section 4.4.1) is also used for heating. Cooling is also
enabled dependent of process temperature .
Parameters to be adjusted: F.H2O: adaptation of (non-linear) characteristic
( PArA / Cntr) Water cooling
t.on: Pulse duration water cooling
t.off: min. pause water cooling
E.H2O: min. temperature for water cooling
Configuration level
Switching behaviuor 50 8800 process controller
-95% -67% -80% -100% -92% -90% -87% -82%
t.off t.on
0
10
20
30
40
50
60
70
-100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5
Controller output [%]
Water cooling non-linear, =1 F.H2O
Water cooling non-linear, =2 F.H2O
Water cooling non-linear, =0,5 F.H2O
Water cooling linear
Parameter:
t.on = 0.4 sec
t.off = 0.2 sec
Effective
controller
output