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STEEkW ed 01/06 EOLO Extra kW
Technical DocumentationTechnical Documentation
Outputs.
It is a unipolar relay for controlling the circulator (M30) that is energised when its ope-
ration is requested.
Circulator relay
(K3)
is is a bipolar relay that is excited when the burner has to be ignited.
By means of its contact, boiler ignition is enabled.
Request relay
(K2)
It is a d.c. signal that controls the modulation coil and with this it is possible to vary
pressure of the gas to burner according to the output required.
Gas valve modulator
(Y2)
is is a signal that lets the zone control unit know the operating status of the appliance
(domestic hot water/central heating) and to recognise the CAR, if mounted, as the room
thermostat of zone 1 (see Zone control unit technical data sheet operation).
Zone control unit (CZ)
(external optional)
It is a signal (BUS) by means of which it is possible to see – on the remote control display
- boiler temperature, operation either in the domestic hot water or central heating phase,
the codes of the alarms triggered and the temperature measured by the external probe (if
installed).
Remote control
(CAR)
(see CAR operation)
Adjustments.
Gas type selector switch
Natural gas/LPG
(S8)
Depending on the position (Natural gas/LPG) it adapts the modulating parameters to the
type of gas the boiler is set for.
is is a unipolar relay that controls the fan (M20) that is excited when its operation is
requested.
Fan relay
(K4)
With this relay the electric 3-way diverter valve (M30) motor (M) is powered.
It is excited with a central heating request, it remains idle with a domestic hot water
request.
3-way diverter valve relay
(K1)
It is a 230 V ac signal indicating that the main gas valve coils are
energised (Y1).
Gas valve power supply
(Y1)
230 Vac = coils
energised
0 Vac = coils not
energised
It is a high voltage signal (higher than 16 kV) that determines an electrical discharge at the
ends of the ignition electrodes located on the burner.
Ignition electrodes
(E1)
It is a d.c. signal that controls the relay board circuits.
Relay board piloting
(external optional)
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