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Optima 310
2. Function
2.1 Description Optima 310
A Combi unit is used for heating up domestic water and
supply air, to provide partial cover of the ventilation and
basic ventilation heating needs in the home.
1: Domestic water heating
The domestic water temperature is controlled by sensor
T8, which is mounted at the base of the tank. When
the need for heating of domestic water arises, the
compressor starts, the magnetic valve MA 3 and MA
6opens and the water is heated to the temperature set
(point 5 in the operating menu).
2: Room heating
By room heating the magnetic valve MA 2 and MA 5 is
activated.The room temperature is controlled by room
sensor T2, mounted on the control panel. If, for example,
this temperature has been set to 21°C, the compressor
will start up when the room temperature has fallen to
20.6°C. When the compressor has heated the room
temperature up to 21.4°C, the compressor will stop. If
the compressor cannot maintain the room temperature,
the motor valve (unit with water after heating coil) will
begin to perform temperature control (PID control) when
the room temperature has fallen to 20°C. For units with
electric after heating coils (level 1), this will cut in when
the room temperature has fallen to 20°C. When the room
temperature again reaches 20°C, the electric heat will
switch off. Units with electric pre-heating coils will control
the same way as units with after heating coils.
3: No heating needs
When there is no need for either water heating or room
heating, the compressor will stop, while the fans continue
to run. The heat in the extract air is recovered in the
counter current heat exchanger and transferred to the
supply air.
4: Defrosting
When the temperature difference between the
temperature upstream of the cooling coil and the
temperature of the cooling coil becomes too large, as
happens when ice is formed on the cooling surface, the
unit goes into defrost mode. The magnetic valve MA 4
opens and the supply air fan and the electric heating coil,
stops until the ice has melted and the cooling coil has
reached a temperature of app. 5°C. Then the magnetic
valve closes again and the supply air fan and electric
heating coil restart operation.
2.2 Extra capacity
Electric element:
If the hot water need is larger than the coverage of the
Combi, the electric heating element may be set to ON
in the main menu with a short-cut key. When the electric
heating element is ON, sensor T7, mounted in the middle
of the tank, will control heating up the upper half to the
set temperature (point 7 in the operating menu)
2.3 Operation safety
High pressure switch:
To prevent the compressor exceeding its range of
application, there is an integral high pressure switch,
which interrupts when the pressure becomes too large.
Activate the red reset button once the cause of the error
has been identified.
Circuit safety breaker:
If an error should occur in the electric heating element,
the safety breaker thermostat will disable the heater. To
reset the safety breaker the centre button of the safety
breaker must be pressed. The safety breaker is located
on the heater. (Remember to disconnect the power
supply to the unit, before any work is carried out)
Override control of supply air fan:
If the supply air temperature rises to over 45°C, the
speed of the supply air fan will begin to rise, in attempt to
stabilise the supply air temperature at 45°C.
2.4 Warnings
Filter timer
To ensure that the filters are changed, and an optimal
operation is maintained, the controller has a filter timer
(please se point 14 and 15). When the timer reaches
the chosen value the display will read “change filter” and
the red Genvex logo will flash until the filters has been
changed.
Data error
This error will be shown, if no communication is possible
between the display and controller. Please control the
cable connection on the clips 21 – 24.
Frost alert
This error is shown if a water coil is installed in the
system and the temperature of the water coil is to low.
Then there is a risk of frost damage. The controller will
stop the unit and open the valve to the water coil to keep
the coil warm.
Pressure switch error
When the high pressure switch interrupts, the display will
read “Pressure switch error” and the red Genvex logo will
flash until the red reset button is activated.
