Ferroli Domina Oasi F 24 E, Техническое руководство, Страница: 30 / 40

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DOMINA OASI F 24 - 30 E
FERELLA BOIL F 24 - 30 MEL
KEA AIR COMPACT E
Version - 09.2002
3. OPERATION
3.1 Operating principle
When there is a call for heating, the circulator and fan start working; then the air pressure switch enables
the control and safety unit to ignite the burner. Via the electronic flame modulation system, the boiler
capacity is gradually metered till it reaches the set delivery temperature. If the power needed for the heating
plant is lower than the minimum boiler power, when the delivery temperature exceeds the setting of 6°C, the
burner switches off and the electronic system enables re-ignition only after another 2 minutes. On reaching
the set ambient temperature (room thermostat), the burner switches off and the circulator keeps on working
for another 6 minutes to enable better heat distribution throughout the system. If hot tap water is called for
during the heating phase, the electrical heating circuit automatically turns off and the hot tap water production
circuit switches on. Throughout this phase the heating system circulator stops and the primary circuit
circulator starts up to heat the boiler. The boiler detects the tap-water temperature via the NTC sensor. The
call for tap water is active when the boiler tap-water temperature measured by the sensor is at least 1°C lower
than the temperature set on the potentiometer “C” of the control panel. The call ends when the boiler
temperature exceeds the temperature set on the panel by 1 or 2°C.
Test function
Bridging the terminals of connector X5 turns on “Test” operation. In this mode the boiler works as in heating
mode, but tap water operation, idle time and modulation are turned off. The test lasts 5 minutes.
Heating post-circulation
After the call for heating, the circulator performs "post-circulation" for approximately 6 minutes to prevent
thermal inertia and balance the system boiler temperature.
Boiler post-circulation
After the call for tap water, the boiler circulator stays in operation for another 2 minutes to prevent thermal
inertia and deliver the heat of the exchanger to the tap water. At the end of the two minutes, the boiler can
start heating immediately if this is called for.
Circulator anti-locking
If not used for 24 h, the circulator is turned on for a few seconds to prevent it locking due to an extended
stoppage during summertime operation.
Gradual starting on heating (gradual increase in heating temperature)
The time to reach the maximum heating temperature is 5 minutes.
Limit thermostat
The 88°C limit thermostat coming on causes the burner to switch off momentarily via the ignition unit and
the heating circulator to start up.
Antifreeze protection
The antifreeze function is turned on by the heating temperature sensor when the temperature falls under 5°C.
In this phase, both the burner and the circulator start working. When the temperature reaches 15°C, the
burner switches off while the circulator keeps on working for another 6 minutes.