Thermostat for adjustment - maximum value - minimum value
Electronic adjustment thermostat by means of information relayed from a PT100 probe immersed in the oil in the
delivery manifold, the thermostat adjusts spray temperature. (The correct conditions for fuel spray are shown in the
temperature/viscosity graph below).
2
mm
/s
°E
Example: fuel oil with 7 °E viscosity at 50 °C is pre-heated to approximately 110 °C.
Note: although the temperature set on the thermostat should correspond to the temperature of the fluid, it is good
practice to check that the thermometer shows the correct reading once the unit has been in operation for a few min-
utes. The LED will illuminate to indicate that the heating resistances 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 permissive 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 resistance
when, because of failure of the adjustment thermostat, the tempera-
ture of the pre-heater increases to unacceptable levels; a "high tem-
perature" alarm output is provided on the burner terminal strip.
(Factory setting is approximately 180°C).
Renewing the minimum and maximum temperature thermostats.
Reposition the probes of the new thermostat, after having first loos-
ened the plate pack securing screws. Make sure that the probe is
touching the resistance and the plate pack as shown in the adjacent
figure. The same precautions should be taken when renewing the re-
sistances in contact with the thermostat probes.
If the pre-heater should malfunction, use an ohmmeter to check that the resistances located in contact with the tem-
perature probes are not burnt out (reading of approximately 35 Ohm).
Changing the PT100 probe in the oil delivery manifold:
Fit the supplied nut and biconical collar on the new probe, insert a length of approximately 40 mm 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 resistance.
5507
SPRAY TEMPERATURE ADJUSTMENT
Atomisation temperature °C
D2005
Aluminium
plate
Aluminium
plate
D2007
16
GB
Adjustment thermostat probe
Thermometer
Min. temperature
thermostat
D2006
Pre-heater
Max. temperature
thermostat.
Purge
Tubes into aluminium plate
Resistance
Thermostat
probe