Riello PRESS 300 T/N ECO Installation, Use And Maintenance Instructions page 54

4.5 AIR PRESSURE SWITCH
D68
4.6 ATOMISATION TEMPERATURE ADJUSTMENT
Adjustment thermostat - maximum value - minimum value
The electronic adjustment thermostat by means of information relayed from a PT 100 probe immersed in the
fuel oil delivery manifold, the thermostat adjusts the atomisation temperature. (The correct conditions for fuel
Atomisation are shown in the temperature/viscosity graph below).
sq.mm/s ° E
Example: fuel oil with 7 °E viscosity at 50 °C is pre-heated to approximately 110 °C.
Important: although the temperature set on the thermostat should correspond to the temperature of the flu-
id, it is better practice to check that the thermometer shows the correct reading once the unit has been in
operation for a few minutes.
The LED will illuminate to indicate that the heating resistors are working properly.
The minimum temperature thermostat, in addition to shutting down the burner if the fuel temperature falls
below the critical value for correct combustion, this thermostat also provides an enabling signal at the time
of burner start-up.
(Factory set at approximately 80°C, adjustable by removing the pre-heater cover and relative plate).
Maximum temperature thermostat, this switches off the resistor when, because of failure of the adjustment
thermostat, the temperature of the pre-heater increases to unacceptable levels; a "high temperature" alarm
output is provided on the burner terminal strip. (Factory setting is approximately 180°C).
5841
D2746
Atomisation temperature
10
Carry out the regulation of the air pressure switch after
carrying out all the other regulations of the burner with
the air pressure switch adjusted at the beginning of the
scale.
With the burner operating at the MIN power increase
the pressure of the adjustment by slowly turning the
appropriate knob clockwise until the burner locks out.
Then turn the knob counterclockwise to a value equal
to about 20% of the regulated value and then check
the correct turning on of the burner. If the burner locks
out again turn the knob a bit further in a counterclock-
wise direction.
Adjustment thermostat probe
D2747
°C
GB
Thermometer
Min. thermostat
Max. thermostat
2848
Pre-heater
Purge