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STEMkW Special ed 01/08 EOLO Mini kW Special
Technical Documentation
Technical Documentation
Inputs.
It indicates an ongoing d.h.w. request.
After domestic hot water has been drawn it enables boiler opera-
tion in the d.h.w. mode which is given priority over the system
heating phase.
D.h.w. ow switch
(S4)
Closed = d.h.w.
request
It sends operation mode signals (Stand-by / Summer / Winter), temperature adjustment
signals (DHW and central heating) and central heating request signals (time, ambient
temperature, error codes, etc.) to the P.C.B.
Digital remote control
(CRD) (option)
(see CRD function)
It sends signals from the SUMMER/WINTER selector, DHW and central heating tem-
perature and central heating request signals (time, ambient temperature, error codes, etc).
To the P.C.B.
Comando Amico Remoto
remote control (CAR) (op-
tion) (see CAR function)
It sends signals to the P.C.B. regarding function requests from zone valves or external
pumps (see zones control unit function).
Zones control unit (CZ)
(external optional)
It is a switch with clean contacts closing a circuit (low voltage) on
the integrated P.C.B. enabling central heating operation when
ambient temperature is less than desired.
Room thermostat
(S20)
(optional)
Open = Central
heating OFF
Closed = Central
heating
ON
It enables burner ignition by powering K1 relay when ue are
properly discharged.
When “NO” contacts are closed while the fan is switched o, it
will not enable ignition cycle.
Pressure switch
(S6)
Changing contact
e signal indicates ame has been detected.
It allows P.C.B. to increase current to modulation coil (Y2) after limiting current during
the ignition sequence.
It keeps the gas valve (Y1) open.
Flame detection
(E2)
It consists in a resistance which varies according to outdoor
tempera ture.
It allows the integrated P.C.B. to vary the system ow temperature
in relation to outdoor temperature.
External probe (B4)
(optional)
NTC probe
1 kΩ 25 °C
It is a resistance varying according to the primary circuit ow water
temperature.
It is also used as limit thermostat (90 °C).
Flow probe
(B1)
NTC probe
10 kΩ 25 °C
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