M0G140F7-01 06/11/07 pag 23
CONTROL
The HEATING mode functions are active only on HEAT PUMP unit version .
In ONLY COOL units, the relative parameters are VISIBLE but NOT ACTIVE ,
for example the winter setpoint.
ALA
R
M
STATUS
S
ET
OPERING MODES
ON – OFF
Unit can be switched on and off by:
remote or service keypad
remote switch (see ELECTRICAL CONNECTIONS paragraph)
Supervisor
COOLING The compressor is activated with supply temperature higher than set point
ECO
A secondary set-point can be used, with respect to the comfort setting. In heating the
ECO-set is lower than the standard set , in cooling the ECO-set is higher than the
standard set.
MAINTENANCE
the plant can be kept within the operating limits even when the unit is OFF or on
STANDBY
CHARACTERISTICS
THERMOREGULATION
The thermoregulation is based on the SUPPLY temperature.
The unit is dimensioned for a determined TOTAL HEAD between input and output water temperature.
Usually the project step is 5°C; if the value is different, it is necessary reset parameters 37 and 38 (accessible to the service
centre). In function of the total head, the installation determines the head quote that every resource (compressor, heating
elements) is able to provide: the STEP HEAD. The control logic insert gradually the resources when the supply temperature is
higher than the set point + the head step. The resources are activated one at a time and only at the SCAN TIME expiring.
The scan time is not fixed but it changes in function of the margin between the water supply temperature and the Set point
value. Higher is the margin value (both in positive and in negative) shorter will be the space among the scan points.
The scan time value is visualized at status 4; when the status 3 has reached the status 4 value, the compressor operating
request is activated.
What above described, refer to the COOLING operating; in HEATING le logic is the same but “overturned” ( insertion of the
compressor for supply temperature< set-point –step jump )
SUPPLY temperature
head step
ACTUAL set point
SUPPLY temperature SURVEY,
at SCAN TIME expiring
time
VARIABLE scan time
SET-POINT COMPENSATIONS
The compensations are evolved functions to protect the compressors and to adapt, as far as possible, the unit operating to the
installation and use characteristics.
The compensations prolong the compressor operating time and limit the start number; to do this they delay the compressor
insertion point adding an offset.
COMPENSATED compressor activation point
non compensated compressor activation point
offset by compensation
ACTUAL set point
• The compensation on the DURATION is useful when the installation water content is limited.
• The compensation on the CHARGE is useful if the variable charge is present.
For the enabling and the configuration is necessary the parameter modification with reserved access to the service centres.
In industrial applications where is requested a temperature check is possible to disable the COMPENSATIONS.
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