Technical documentation
Technical documentation
STEM@ ed 06/01
27
EOLO MAIOR @
EOLO 21 / 24 / 27 Maior
@ OPERATING SEQUENCE
Heating phase
D.h.w. phase
POWER SUPPLY
POWER SUPPLY
Main switch in WINTER position
(SUMMER if CAR is fitted)
Main switch in SUMMER or WINTER position
(
SUMMER if CAR is fitted)
⇓
⇓
POWERING MODULATION CARD
AND
CAR (remote control)
POWERING MODULATION CARD
AND
CAR (remote control)
Closing the contacts of the main switch powers the
modulation card, the remote control
(if fitted)
and
enables the central-heating function
Closing the contacts of the main switch powers the
modulation card, the remote control
(if fitted)
and
enables the d.h.w. function
⇓
⇓
CLOSING OF THE ROOM THERMO.
SWITCH
/ CAR FUNCTION REQUEST
CLOSING OF D.H.W. SWITCH
Request of room thermostat or CAR
(if fitted)
detects
conditions requiring operation in central-heating phase
D.h.w. request
⇓
⇓
POWERING PUMP
The modulation card powers the circulator
⇓
POWERING THE IGNITION UNIT
If the contact of the system water pressure switch is closed, the modulation board controls the
ignition card
⇓
FLUE PRESSURE SWITCH CONTACT CONTROL
The unit checks the correct position of the flue pressure switch
(normally closed NC contact)
⇓
POWERING FAN
The ignition card powers the fan
⇓
FLUE PRESSURE SWITCH CONTACT CONTROL
The ignition cards checks deviation of the flue pressure switch contact following fan operation
(contact normally open NO)
⇓
POWERING THE IGNITION ELECTRODES
The ignition card powers the ignition electrodes
⇓
POWERING THE GAS VALVE COILS
With the consensus of the overheating thermostat, the unit powers the main gas valve (Y1)
coils
⇓
BURNER IGNITION (SOFT)
When the gas valve has been powered, the board conveys soft ignition current to the
modulation board (Y2) for 5 seconds
⇓
FLAME DETECTION
By means of the ionisation electrode, the unit detects burner ignition and terminates the
ignition cycle
⇓
BOILER OPERATION
The burner operates at variable output according to the type of request, to the
adjustments/settings made and to the temperatures read by the NTC sensors