M6G240F7-02 14/03/08
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
RM
ST
AT
US
SE
T
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 outlet temperature higher than set point
To switch from
cooling
to
heating
and vice versa, proceed as follows:
Turn the unit OFF
Wait until the plant water temperature (and external air) fall within the operating limits.
They can be switched over from the remote controls (refer to the ELECTRIC WIRING
paragraph).
HEATING
The compressor is activated with outlet temperature lower 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
DEFROSTING
The external coil is free from ice stopping the fans and forcing for a short period the
unit in cooling
CHARACTERISTICS
THERMOREGULATION
The thermoregulation is based on the OUTLET 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 outlet 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 outlet 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 outlet temperature< set-point –step jump )
OUTLET temperature
head step
ACTUAL set point
OUTLET temperature SURVEY,
at SCAN TIME expiring
time
VARIABLE scan time
