EVCO S.p.A.
EVDRIVE04 | User manual ver. 1.1 | Code 144EPD4I114
Page 28 of 78
SH parameters set selection
(SetP) supports switching from one control parameter set to another simply and quickly.
It is possible to change the regulation parameter sets directly by modifying
SH parameters set selection
(Pr04), if a
serial interface is present, or via correctly configured digital inputs on the standalone version. If one of the digital
inputs (DI1 or DI2 or DIHV) is configured as "Change SetP" (
DI1 function
(Ph11) or
DI2 function
(Ph21) or
DIHV
function
(Ph31) setting to 2), the parameter sets for the PID control are determined by the digital input status: set 1 is
selected if the input is low, set 2 is selected if the input is high. If no DI is configured for parameter set modification,
the data is taken directly from
SH parameters set selection
(Pr04).
With the operation mode selected, the regulator uses the related SH set-point parameter. This is a fundamental
parameter for the proper functioning of the control algorithm. A low set-point ensures a higher evaporator
performance, lower temperatures, and minimum variations, but has the disadvantage that liquid may reach the
compressor.
The algorithm uses different regulation parameters, depending on the working area:
-
if the measured error is lower than 0 an aggressive normal control is performed.
-
else if the measured error is in the dead band (error lower than Dead band threshold (parameter Pr10)) there
is no changing in valve opening.
-
else if the measured error is in the smart band (error lower than Smart band threshold (parameter Pr11)) a
smart algorithm is used.
-
else a normal PID control is performed
If the measured error is lower than
Fast action threshold
(parameter Pr13) at the above operation the "Fast Action"
algorithm is added which further strengthens the algorithm response
All the input parameters, with the exception of the
Main control type
(Pr01), are acquired at every main cycle.
