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41
AST 14 C 258/00
BOILER TYPE SETTING
This board is arranged to manage 3 different types of boiler according to the setting of
parameter P3 (see paragraph on page 34):
P3 = 1
combi instant plates
P3 = 2
heating only
(future implementation)
P3 = 3
with water heater
(future implementation)
IGNITION PHASE AT PRE-SET POWER
Upon every operation request entailing burner ignition,
burner will be ignited with a pre-set power by means of
parameter P6 (fan speed at burner ignition power). Once
flame is detected, the following flame propagation phase
will be started .
FLAME PROPAGATION PHASE AT PRE-SET POWER
During the flame propagation phase, for 4 sec, the power
provided to the burner is kept at the ignition power value
(P6) to allow the flame propagation. At the end of such
propagation, the next step is the adjustment of the
required functions (DHW, heating, anti-freeze or flue
cleaning).
AUTOMATIC FLAME CONTROL
Upon an operation request (DHW or heating) fan will be powered; it will be considered
active if a higher speed than the maximum rotation speed (700 rpm) is detected for 1.5
seconds (TW room pre-cleaning waiting time). If the fan rpm number is within the
tolerance (300 rpm), the igniter and the gas valve are powered. The igniter is excluded in
case of flame presence or a second before the TS safety time (10 sec).
If the flame does not appear during one ignition attempt at "cold" system (without
detection) within the TS safety time, the automatic flame control automatically closes the
gas valve and repeats the ignition sequence maximum 5 times with a 5-second room
cleaning cycle after each attempt. In case no flame is detected during the last attempt
within the TS safety time, the flame control switches to the flame control lock status. In
case the flame disappears during the TS safety time, the ignition transformer is reactivated
without interrupting the gas valve power supply, and with fan turning at the same ignition
speed.
If the flame disappears after a standard operation (after the safety time), the automatic
flame control repeats the ignition sequence and carries out only one ignition attempt after
a 5-second room pre-cleaning.
The flame control switches to shutdown status even when a flame is detected with burner
off (parasitic flames) for a time higher than TW+TS value.
