Operating Cycle - Lamborghini Caloreclima 310 PM/M-E Handbuch

OPERATING CYCLE

Depending on the device to which the air valve operation servo control is interlocked, the burner can operate in
two different modes: gradual two-stage, if the control organ is of the on/off type, continuous flame modulation
if the device is of the modulating type.
GRADUAL TWO-STAGE OPERATION
2nd stage
1st stage
ignition
0
a
This is obtainable with standard open/close (on/off) boiler thermostat (or pressure switch) so by means of
the servo control, the air valve operates in two positions : minimum (1st stage) or maximum opening (2nd
stage).
We have gradual two-stage operation because change from one to the other takes place gradually and
smoothly.
a) Stop sequence: with the burner stopped, the air valve is in closed position to prevent the air from
entering and cooling the combustion chamber of the boiler and stack.
b) Preventilation sequence: the air valve is in fully open position with subsequent return to partially
closed position corresponding to the ignition capacity (with gas flow always closed).
c) Ignition flame formation sequence: the electronic gas coil is energized and the gas regulator
is partially open in relation to the pressure of the ignition air.
d) Main flame or second stage switchover sequence: the servo control commands opening of the
air (up to maximum setting capacity) and the increase in pressure causes a gradual increase in gas flow.
e) Maximum delivery to first stage switchover sequence: the boiler thermostat/pressure switch
(regulator) commands the servo control to close the air.
The consequent pressure drop at the burner head causes the gradual reduction of gas flow until minimum
delivery is achieved.
The burner repeats switchover from first to second stage or from second to first stage and comes to a
complete stop, always in relation to the command given by the boiler regulator to the servo control.
AIR
GAS
b c d
e
1 sec. max
operation
2
time
a