42
EN
2.6
Electrical control and command equipment
The EBR-M14 command and control electrical equipment con-
trols and monitors the burner’s operation. The microprocessor
controls the programme’s sequence and guarantees maximum
stability of the cycle times, regardless of any fluctuations in
the supply lines or of the room temperature. The control unit
is made with materials that guarantee protection against the
potential consequences caused by open flames. Whenever the
supply voltage drops below its minimum rated level (70 ± 8 V),
the control unit locks out, even if no error signal appears. It swi-
tches back on after the supply voltage rises again above (190 ±
8 V).
2.6.1
Operating function
– If there is a heat request (green LED lit), the command and
control unit will start the programme’s sequence.
– The heater heats the diesel in the oil line.
– When the optimal temperature is reached, the motor starts,
the ignition transformer activates and the 15-second pre-ven-
tilation phase starts.
– During the pre-ventilation phase, the burner is monitored
through the flame signal.
– Once the pre-ventilation phase terminates, the diesel sole-
noid valve opens, the flame ignites and the burner starts.
– The ignition transformer remains engaged for the entire du-
ration of the post-ignition phase.
2.6.2
Controlled stoppage
Controlled stoppage occurs if:
– the boiler thermostat interrupts the heat request;
– the oil solenoid valve closes and the flame goes out;
– the 15-second (factory-set time) post-ventilation cycle starts,
after which the motor stops;
– the burner enters the stand-by mode pending a new heat re-
quest.
2.6.3
Safety function
A safety shutdown occurs if:
– during the pre-ventilation phase there is a flame signal (flame monitoring);
– the flame has failed to ignite within the safety interval (5s from the opening of the fuel solenoid valve).
A safety shutdown is signalled by the lock-out indicator light (lit steady red).
The operating conditions can only be restored (reset) once the cause of the lock-out has been eliminated and the reset button (9) has
been pressed, as illustrated in “Fig. 2”.
Boiler
temperature
control
General
power
supply
Motor
Ignition
Transformer
Fuel solenoid
valve
Flame check
Flame
Pre heater
-
-
tr
th
to
tp
ts
tpp
tpi
LINE
C
15s
10s
5s
7s
<400s
15s
to
Stand-by: the burner waits for the
heat request
tr
Heating time
th
Stabilisation time
tp
Pre-ventilation time
ts
Safety time
tpi
Post-ignition time
tpp
Post-ventilation time
Fig. 6
