Technical documentation
Technical documentation
STEM@ ed 06/01
25
EOLO MAIOR @
OUTPUTS
Modulation coil
(Y2)
This is a D.C. current that controls the modulation coil and permits changing the pressure of
the gas to the burner depending on requested output.
Control zone unit (CZ)
(external optional)
This is a signal that enables the zone unit to know the operating condition of the appliance
(d.h.w./central heating
) and to recognise the CAR, if fitted, as room thermostat of zone 1
(see control zone unit operation).
Remote control (CAR)
(external optional)
(see CAR operation)
This is a signal that permits displaying on the monitor of the remote control the temperature
of the boiler, operation in d.h.w. or central-heating modes and the codes of the tripped
alarms.
Pump relay (K1)
This is a unipolar relay for controlling the circulator (M1). It is powered when operation is
requested.
Request relay (K2)
This is a unipolar relay which is excited when the burner needs igniting.
When its contact closes, the ignition unit is powered.
Reset
In the event of the Remote Friendly Control being installed
(optional
), this
signal permits
releasing the ignition unit after the overheat. safety device (E4) and the stack safety device
(E5) have tripped or after ignition failure
This operation is performed on the remote control panel
(see CAR operation).
ADJUSTMENTS
Central-heating potentiom.
(C.H.)
This permits setting the temperature of the central-heating water between 38 ºC and 85 ºC.
D.h.w potentiom. (D.H.W.)
(combined models only)
Permits setting the temperature of the d.h.w. between 30 ºC and 60 ºC.
Natural gas/LPG switch
(S1)
Depending on its position
(natural gas/LPG)
it adapts the modulation parameters to the type
of gas for which the boiler is set.
D.h.w. modulation switch
(S3)
(B&P board only)
By eliminating this bridge, in d.h.w. phase the burner is kept
operating at minimum output even after reaching the temperature set
with the d.h.w. potentiometer (D.H.W.).
When the temperature read by the d.h.w. sensor (B2) exceeds 65°C,
the burner is switched off and is relit when the temperature drops
below 64 ºC.
absent = modulation
and switchoff at 65 ºC
present = modulation
and switchoff at set
temp.
Central-heating timing (S2)
At every switchoff due to the temperature having been reached in
central-heating phase, a delay of 180 s is entered (
standard
) or of 30
seconds until switching back on for the same request.
absent = 30 s
entered = 180 s
C.H. max power trimmer.
(C.H. MAX POWER)
Permits adjusting max output in central-heating phase and adpating this to system
requirements
(from minimum to maximum set on gas valve).
C.H. min power trimmer.
(C.H. MIN POWER)
Permits adjusting modulated min output in central-heating phase
(from minimum up to 2/3 of
maximum set on the gas valve).
Adjustment is possible during the first 60 seconds after ignition in central-heating phase.
Soft ignition trimmer
(IGN. POWER)
Permits adjusting power to the modulation coil and therefore gas pressure to the burner
during ignition phase
(from min up to 2/3 max set on valve).
Adjustment must be made with the d.h.w. probe (B2) electrically diconnected and can be
made within the first 30 sec of operation in central-heating phase.
