CLIVET TALK User Manual

Data creazione 10/09/03 DS03I009GB--00 Pagina 45 di 59
OPERATION OF THE TEMPERATURE CONTROLLER
COOLING
The temperature controller acts by comparing the water outlet temperature to the system (average of the
evaporator water outlet temperatures), against the current set point, and considering a number of threshold
values.
The temperature controller will tend to deactivate capacity-control steps when the water outlet temperature
falls below the current set point
Vice-versa, it will tend to activate capacity-control steps when the outlet temperature exceeds the sum of
current set point + the theoretical value of the temperature difference between the water inlet and outlet due
to an individual capacity-control step. (This value may differ between compressors, according to the values
assigned to the parameters PotC1, PotC2, PotC3) + any offset due to the compensation functions.
NB: The following are exceptions:
1) Activating the first capacity-control step. In this case, the temperature controller waits for the
water outlet temperature to reach the step activation value (see above) + an hysteresis set for
the parameter IsFirstStep.
2) Deactivating the last active step. In this case, the temperature controller can deactivate the step
only if the temperature falls below the set point by the value set for the parameter IsLastStep.
3) The temperature falls below: current set point – the value of the parameter PreeFree. In this
case, all the active capacity-control steps are deactivated, irrespective of the scan time
(immediate action). In any case, the compressor safety times are observed.
DETERMINING THE TEMPERATURE DIFFERENCE FOR EACH COMPRESSOR
Parameters involved:
Description Limits UOM Default
Percentage of capacity delivered by compressor 1 PotC1 % 25
Percentage of capacity delivered by compressor 2 PotC2 % 25
Percentage of capacity delivered by compressor 3 PotC3 % 25
The temperature difference due to a compressor will be calculated as follows:
Temperature difference due to C1 = ((PotC1 / 100) * DeltaTC)
Temperature difference due to C2 = ((PotC2 / 100) * DeltaTC)
Temperature difference due to C3 = ((PotC3 / 100) * DeltaTC)
Step difference
IsFirstSte
IsLastSte
Current set point
No activation zone
Zone in which the
first step can be activated
Zone in which the steps can be activated
Zone in which the steps can be deactivated
Zone in which the last step can be deactivated
+
+
Time
Temperature
a
Scan
time
Scan
time
Scan
time
Scan
time
Scan
time

CLIVET TALK Specifications

General

Brand	CLIVET
Model	TALK
Category	Controller
Language	English