5840
10
GB
4.6
ATOMISATION TEMPERATURE ADJUSTMENT
Adjustment thermostat - 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 the atomisation temperature. (The correct conditions for fuel
Atomisation are shown in the temperature/viscosity graph below).
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
fluid, 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 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).
Replacing the minimum and maximum temperature
thermostats.
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 adjacent figure.
The same precautions should be taken when renewing the
resistors in contact with the thermostat probes.
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).
Changing the PT 100 probe in the oil delivery manifold.
Fit the supplied nut and bitapered 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.
°C
sq.mm/s
°E
Atomisation temperature
Visco
sity
a
t 50
° C
D2746
D2747
Thermometer
Adjustment thermostat probe
Pre-heater
Purge
Min. thermostat
Max. thermostat
Thermostat probe
Resistor
Tubes into aluminium plate
Plate
D2751
