Level – West Control Solutions Pro-16 User Manual
Page 43

Configuration
level
9499-040-93811 / 59537-1
Page 43 of 88
Pro-16
short on and off pulses. The shortest pulses result from ¼ x
t1 or ¼ x 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]
4.3.4
Switching attitude linear (
CyCl=1)
For heating (
Y1), the standard method (see chapter 4.3.3) is used. For cooling (Y2), a
special algorithm for cooling with water is used.
Generally, cooling is enabled only at an adjustable process temperature (
E.H2O),
because low temperatures prevent evaporation with related cooling, whereby damage to
the plant is avoided. The cooling pulse length is adjustable using parameter
t.on and is
fixed 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) x 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