Riello PRESS 140 T/N ECO Installation, Use And Maintenance Instructions page 54

4.6 ATOMISATION TEMPERATURE ADJUSTMENT
Thermostat for adjustment - maximum value - minimum value
Electronic adjustment thermostat by means of information relayed from a PT 100 probe immersed in the oil in
the delivery manifold, the thermostat adjusts atomisation temperature. (The correct conditions for fuel atomisa-
tion are shown in the temperature/viscosity graph below).
Adjustment thermostat probe
sq.mm/s ° E
D2746
Thermometer
Min. thermostat
Max. thermostat
D2747
°C
Pre-heater
Atomisation temperature
Purge
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.
Minimum temperature thermostat, in addition to shutting down the burner if the fuel temperature should
fall below the critical value for correct combustion, this thermostat also provides a enabling signal at the time
of burner start-up.
(Factory setting 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).
Replacing the minimum and maximum temperature
thermostats.
Tubes into aluminium plate
Reposition the probes of the new thermostat, after having
first loosened the plate pack securing screws. Make sure
that the probe is touching the resistor and the plate pack as
shown in the figure opposite.
Plate
The same precautions should be taken when renewing the
resistors in contact with the thermostat probes.
Resistor
If the pre-heater should malfunction, use an ohmmeter to
check that the resistors located in contact with the temper-
ature probes are not burnt out (reading of approximately
35 Ohm).
D2751
Changing the PT 100 probe in the oil delivery manifold.
Thermostat probe
Fit the supplied nut and bi tapered collar on the new probe,
insert a length of approximately 40mm in the manifold, and
secure firmly into place. At this point, the section remaining
outside the manifold can be bent as required, with no risk of
damaging the resistor.
2915839
10 GB