Technical documentation
Technical documentation
STESP ed 02/02
19
EOLO SUPERIOR PLUS
MODULATION CARD
The boiler is equipped with a microprocessor-controlled electronic board used on both the models with 3-way
electric valve (
Zeus Superior, Eolo Superior Plus
) and on the models with central-heating and d.h.w. pumps
(
Hercules
).
The different type of operation is obtained by adjusting
diode D9
(diode engaged = electric 3-way valve,
diode disengaged = double pump).
The board is connected to a terminal board (DISPLAY CARD) which, by means of LEDs and a display panel,
indicates the state of operation of the appliance.
The board is powered with master switch (IG) in position
(summer)
or
(
winter)
.
Central-heating request with room thermostat
With the main switch in WINTER position and the contact of the room thermostat (TA) closed, the low-
voltage circuit starts the circulator (MP) by means of relay “RP” and powers the motor (M) of the 3-way valve
(VD) through the contact of relay “R3V”.
The circulation of water results in the closing of the pump pressure switch (SP) which, because it is connected
in series to the NC contact of the flue pressure switch (SV) powers the coil of relay “K5”.
If the temperature detected by means of NTC central heating sensor (NR) is below that set on the control
panel by means of the central heating potentiometer (RISC), the adjustment circuit excites relay “K5” and
starts the fan (MV) controlled by relay “RV”.
The consequent deviation of the contact of the fume pressure switch (SV) results in relay “RT” being powered
and the relevant contact closing.
This powers the control unit (IGN. CARD) and starts the ignition cycle.
During the ignition phase, the power to the modulation coil is restricted by the adjustment made with the slow
ignition trimmer (POT ACC.).
Once the flame has been detected
(signal from control unit)
, the signal to the coil (MOD) is changed in a
manner directly proportionate to the difference between the temperature set with the central-heating
potentiometer (RISC) and that detected by means of the NTC central-heating sensor (NR) and, if necessary,
reaches maximum set value in 50 seconds
(maximum central-heating output).
When the set value is exceeded, the contact of relay “RT” is opened with consequent switch-off of the burner.
Re-ignition of the burner for the same request remains inhibited for 180 s / 30 s.
Central-heating request with Remote Friend Control
If the conditions detected by the remote control (CAR) require ignition in central-heating phase (
SUM/WINT
switch of CAR in WINTER position, time programmer request, room temperature setting above that found
),
the low-voltage circuit starts the circulator (MP) by means of relay RP and powers the motor (M) of the 3-way
valve (VD) by means of the contact of relay “R3V”.
