36
INITIAL PIPING FILL
After checking that the protective plastic plugs placed inside the pump couplings have been removed, proceed as follows:
1) Turn the switch on the burner to “O”.
This prevents automatic ignition of the burner and, in particular, prevents the heating elements being switched on,
components which, if left on with the tank empty could burn out.
2) Make sure, if the burner is three-phase, that the motor turns anticlockwise (when looking at the burner from the
pump side). Direction of rotation can be ascertained by observing the direction of fan rotation via the spy-hole on
the rear end of the worm screw. To start the motor close the relay switch manually (by pressing on the mobile part)
for a few seconds and observe which way the fan turns.
Should it be necessary to invert rotation switch over two phases on the power line input terminals (L1 - L2 - L3).
Note: To be sure which way the fan is rotating wait for it to slow down as it may otherwise give the onlooker a
false impression.
3) Remove (if already connected) the flexible hoses from the aspiration and return piping.
4) Immerge the end of the flexible suction hose in a recipient containing lubricating oil or fuel oil (do not use low-
viscosity products such as light oil, petrol, kerosene etc).
5) Now press the mobile part of the motor relay switch to start the motor and therefore the pump.
Wait until the pump has aspirated a quantity of lubricant equivalent to about 1 or 2 cups, then stop. This operation
serves to avoid the pump working on empty conditions and to increase suction capacity.
N.B. Pumps operating at 2800 rpm MUST NEVER run on empty as they will quickly seize.
6) Now connect the hose to the suction pipe and open all its dampers and all other fuel interception devices.
7) Now press the mobile part of the relay switch once again to start the pump; this will draw the fuel from the tank.
Note: Where piping is long it may be necessary to release air via the vent plug. If the pump is not equipped with
such a plug remove the pressure gauge attachment plug. In this case, when the fuel is seen to flow out of
the pressure gauge coupling hole stop and replace the plug.Then continue filling until the tank is full (the
preheating tank is full when fuel is seen to flow out of the return hose which has not yet been connected).
8) Connect the return hose to the piping and open the gates situated on this pipe. The burner is now ready for ignition.
DESCRIPTION OF OPERATION
(see diagram N° 0002900445 and N° 0002900564)
NOTE
: The “D” (dense) version burners are equipped with an auxiliary element for the pump, the atomization unit and
for the two solenoid valves. In addition, the line filter is preheated.
By closing the switch on the burner the heating elements relay switch is turned to ON (if the relative thermostat so
allows). Voltage arrives at the elements relay switch via the regulating thermostat contact. Once the heating elements
have been switched on they heat the fuel oil in the preheating tank. When the fuel oil temperature reaches a certain
point the minimum thermostat goes off. When the latter is off (and if the other regulation and safety thermostats
provide consensus) the current will arrive at the control box which switches on the burner devices as per the preset
program. The ignition transformer is switched on at the same time as the burner motor (with the OR 3/B control box).
However, with the LAL 1.25 control box the transformer is switched on a few seconds later. The motor turns the fan
which preventilates the combustion chamber with air and simultaneously drives the pump which circulates the hot oil
through the ducts and expels the cold oil and any gas (via the return). This “preventilation” stage terminates when
solenoid valve n° 7 closes (open in its home position), interrupting oil discharge towards the tank. Solenoid valve
closure is followed by an increase of pressure in the delivery pipes.
NOTE:
The preheater net filter incorporates an “anti-gas” spring valve which opens and allows fuel to flow only on
attainment of a pressure of 2 - 2.5 bar. The purpose of this valve is to keep the preheater under slight pressure
even with the burner off so as to reduce, and preferably avoid, gas formation with the oil hot and the burner off.
As the pressure loss caused by this “anti-gas” valve is about 2 - 2.5 bar it is therefore necessary to raise
atomization pressure (pump pressure) in order to compensate for that loss. In practice it will be necessary to
adjust pump pressure to 27 bars. When this pressure reaches 16 bars the nozzle n° 4 closure device in the
atomization unit opens; this allows the oil to reach the nozzle of the 1st stage and from here to enter the
combustion chamber in a finely atomized state. Pressure stabilizes at around 27 bars because the pump
pressure regulator is set at this value. As soon as the atomized oil leaves the nozzle it is ignited by the spark
from the electrodes. During 1st stage ignition the servomotor keeps the air flap in a set position according to
the quantity of fuel burnt. If a flame is ignited properly the shutdown position is passed, the ignition transformer
is switched off and the 2nd stage n° 8 solenoid valve is switched on (closed in the home position).
