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STEEkW ed 12/03 EOLO Eco kW
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STEEkW ed 12/03 EOLO Eco kW
Technical Documentation
Technical Documentation
Technical Documentation
Technical Documentation
Integrated board.
Inside
the boiler’s panel there is an integrated microprocessor
controlled board that controls the appliance’s electrical devices
for the linear modulation of burner output and, by means of
LEDs, it shows the operating status of the appliance, signalling
if any of its safety devices have triggered.
e integrated board is the same on all models, both na-
tural draught and sealed chamber
(NIKE/EOLO Maior
kW, EOLO Eco kW)
,
the recognition of different models
is automatically done by the board through the electrical
connections.
e integrated board is always powered regardless of the posi-
tion of the main selector switch (R10).
Operation.
Central heating request.
e central heating phase is enabled when the main selector
switch (R10) is on “WINTER”.
When the room thermostat contact is closed (S20), the inte-
grated board powers the boiler circulator (M1) by means of
relay K3 and, by deviating the contact of relay K1, powers the
motor (M) of the 3-way diverter valve (M30) that continues
working until the limit switch “1” opens when the central
heating position is reached.
In the meantime, if the flue pressure switch (S6) contact is
idle, “NC”, the adjustment circuit powers the fan (M20) by
means of relay K4.
If the contact of the system pressure switch (S5) is closed
(the
pressure measured in the primary circuit is higher than the
mi-
nimum value)
, with the enable of the safety thermostat (E4)
and the consequent switching over of the flue pressure switch
to “NO” (S6), the board provide to supply the coil of K2
request relay.
If the temperature measured by the delivery probe (B1) is be-
low the temperature set on the control panel with the central
heating temperature trimmer, the integrated board energizes
the K2 request relay which closes the 2 contacts allowing to
start of the ignition cycle.
During the first few seconds from when the gas valve (Y1) was
powered, the current to the modulation coil (Y2) is limited to
the predefined slow ignition current.
Subsequently, the burner goes to the minimum pressure value
set with the “Minimum central heating power*”parameter and
after it reaches the maximum pressure value set with the “Ma-
ximum central heating power*” parameter in a time fixed by
the “Central heating timer ramp*” parameter.
After this, the signal is varied in a way directly proportionate
to the difference between the temperature set with the central
heating temperature trimmer (R6) and the temperature mea-
sured with the delivery probe (B1).
When the set temperature is exceeded (+5 °C), the contact
of relay K2 opens and the burner switches off. Re-ignition
time depends on the setting of the “Central heating ignition
timer*” parameter.
Each time the burner is switched off the fan continues working
for 30 seconds.
FUSES
MAIN SELECTOR SWITCH
TRANSFORMER
NAT-LPG
D.H.W.
CENTRAL
HEATING