OPERATING CHARACTERISTICS
Set point in cooling
(factory setting) = 12°C, differential = 3°C.
With outlet water temperatures above 13.5°C, the 1st
compressor activates, whereas with temperatures above
15°C, the 2nd compressor activates.
With water temperatures below 13.5°C, the 1st compres-
sor switches off, whereas with temperatures below 12°C,
the 2nd compressor switches off.
Set point in heating
(factory setting) = 40°C, differential = 3°C.
With outlet water temperatures above 38.5°C, the 1st
compressor activates, whereas with temperatures above
37°C, the 2nd compressor activates.
With water temperatures below 38.5°C, the 1st compres-
sor switches off, whereas with temperatures below 40°C,
the 2nd compressor switches off.
In the event of a temporary power failure, when power
returns, the mode set previously will be retained in the
memory.
COMPRESSOR START UP DELAY
Two functions prevent the compressor from starting up
too frequently.
•
Minimum time since last shut-down 180 seconds.
•
Minimum time since last start-up 300 seconds.
•
Minimum time of operation for each compressor 60
sec.
•
Minimum time for 2nd compressor ON from 1st com-
pressor ON is 360 seconds.
•
Minimum time for 2nd compressor OFF from 1st
compressor OFF is 20 seconds.
PUMP
The electronic board has an output for control of the cir-
culating pump, which starts up when the unit is switched
on in either the cooling or heating mode and switches off
60 seconds after the unit has been switched off.
The water fl ow alarm functions (differential pressure
switch and water fl ow switch) are activated after the fi rst
20 seconds of pump operation, when the water fl ow is
regular.
MICS-C / MICS-CN
FAN SPEED CONTROL
For correct operation of the unit with different outside
temperatures, the microprocessor controls the fan speed
based on the pressure reading from the pressure tran-
sducer, thus enabling heat exchange to be increased
and/or decreased, maintaining the condensing or eva-
poration pressures practically constant.
The fan functions independently of the compressor.
FROST PREVENTION ALARM
To prevent breakage of the plate-type heat exchanger
due to freezing of the water inside it, the microprocessor
provides for activation of the anti-frost heater if the tem-
perature measured by the exchanger outlet temperature
sensor is below +4°C and stopping of the compressors if
the temperature is below +3°C.
This anti-frost temperature setting can be changed sole-
ly by an authorized service centre and only after having
checked that there is antifreeze solution in the water cir-
cuit.
Activation of this alarm causes the compressor to stop
and not the pump, which remains in operation.
To reset normal functions, the outlet water temperature
must rise above +7°C; reset is manual.
WATER FLOW ALARM
The microprocessor provides for management of a water
fl ow alarm controlled by a differential pressure switch fi t-
ted as standard on the appliance and a fl ow switch to be
installed on the water delivery piping.
Tripping of this alarm shuts down the compressor but not
the pump, which remains active.
I
A
English 06/09
17