Immergas HERCULES Condensing 26 2 E Manual page 44

Technical Documentation
Integrated P.C.B.
Fuse F1
Inside the control panel the boiler is equipped with a P.C.B.
with integrated microprocessor for control of the appliance's
electric devices, which takes care of linear modulation of
burner power.
The display shows the status and functioning mode of the
appliance, indicating any intervention of the safety devices,
with which it is supplied.
The P.C.B. supplied with all models, whether with storage
tank or instant (HERCULES Condensing, VICTRIX ZEUS
Superior kW, VICTRIX Superior kW Plus, VICTRIX Supe-
rior kW) is the same. The different type of boiler functioning is
recognised automatically by means of the appliance's wiring.
The integrated P.C.B. is always powered independently from
the selection made on the main button (
The board carries out a periodical self-check to control its
correct functioning. During functioning in CH mode or with
boiler in stand-by, the function activates every 18 hours from
the last check/powering of the boiler. If functioning in DHW
mode, the self-check starts within 10 minutes after the end f the
withdrawal in progress for the duration of about 10 seconds.
N.B.: during the self-check, the boiler remains off.
Operation.
Central heating request.
By pressing the main button (
bled.
By using button (A) to select functioning in
tioning is enabled in CH mode.
On closure of the room thermostat contact (S20) and if the
system pressure switch contact (S5) is closed (pressure detected
in the primary circuit higher than minimum value)the inte-
grated P.C.B. powers the pump (M1) by means of relay K2,
after which, by diversion of the K4 relay contact it powers the
motor (M) of the 3-way valve (M30). This functions until the
STHCkW ed 0409
).
) boiler activation is ena-
(Winter) func-
42
Technical Documentation
end run switch "1" opens when the CH position is reached.
This leads to the power supply of relay K1 positioned on the
pump relay board (A10) and the consequent power supply of
the CH pump (M2).
If the temperature detected by the NTC flow probe (B1) is
below the setting made on the control panel using the CH
temperature selector, the integrated P.C.B. powers the fan
(M20) and manages the speed.
With the consent of the safety thermostat (E4) and the flue
safety thermostat (E6) and the fan (M20) reaching the "validate
ignition" speed, the integrated P.C.B. allows to start the igni-
tion cycle by controlling, first the ignition electrodes (E1) by
means of the K7 igniter relay and then the K3 request relay,
both the coils of the gas valve (Y1).
The ignition of the burner is detected by the integrated P.C.B.
by means of the ionisation electrode (E2).
During the ignition phase the fan works at a speed equal to one
third the maximum set (see heat output adjustment).
Successively the burner goes to the minimum value set by
means of the "MIN CH.*" parameter setting, to then reach
the maximum value set (if requested) by setting the "MAX.
CH" parameter in a determined time from the setting of the
"CH RAMP" parameter.
Successively, flame modulation takes place with reference to the
difference between the temperature set on the boiler control
panel and that detected by the DHW probe (B1).
On exceeding (+5°C) the temperature set, the contact of
relay K2 is opened with consequent burner switch off, whose
switch/on time depends on the setting of the "Ignition timer"
parameter.
Every time the burner switches off the fan functions for
35 seconds and the pump performs post-circulation for 10
seconds.
WINTER
HERCULES Condensing Export