Manual

prevent unreasonably short on and off pulses. The shortest pulses result from ¼
x t1 or¼x t2. The characteristic curve is also called “bath tub curve”.
Parameters to be adjusted: t1 : min. cycle time 1 (heating) [s]
( PArA/ Cntr) t2 : min. cycle time 2 (cooling) [s]
4.4.2 Switching attitude
linear ( CyCl= 1 )
For heating (Y1), the standard method (see chapter 4.4.1) is used. For cooling
(Y2), a special algorithm for cooling with water is used. Generally, cooling is en-
abled only at an adjustable process temperature (E.H2O), because low temperatu-
res prevent evaporation with related cooling, whereby damage to the plant is
avoided. The cooling pulse length is adjustable using parameter t.on and is fi-
xed for all output values.
The “off” time is varied dependent of output value. Parameter t.off is used for
determining the min “off” time. For output of a shorter off pulse, this pulse is
suppressed, i.e. the max. effective cooling output value is calculated according to
formula t.on /(t.on + t.off) w 100%.
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 coo
-
ling may be negative. The cooling cur
-
ve ensures that the control intervention
with0to-70%correctingvariableis
Configuration level
KS50/52-1 39 KS50-1 cooling functions
-95%
-67%
-80%
-100%
-92%
-90%
-87%
-82%
t.offt.on
0,0
1,0
2,0
3,0
4,0
5,0
6,0
5 101520253035404550556065707580859095
Controller output [%]
relative cycle duration
T/T
1
t1
2xt1
3xt1
4xt1