Spheros thermo 231, Workshop Manual

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2 General Description Thermo 230 / 231 / 300 / 301 / 350
202
2.1 Combustion Air Fan
The combustion air fan supplies the air required for
combustion from the combustion air inlet to the combu-
stion chamber.
The fan consists of a fan motor with fan wheel. Air is taken
in through a splash protection cover or a screen and the
cap. The heaters
Thermo 231 and 301 are provided with
a splash protection cover only.
2.2 Fuel Pump
The fuel pump is responsible for fuel supply.
The pump is driven by the burner motor via a coupling.
Fuel is compressed in the fuel pump to approx. 10 bar and
atomised via the atomiser nozzle.
The solenoid valve integrated into the fuel pump opens
and closes the fuel supply to the atomiser nozzle.
Three different fuel pumps are assigned to the different
heating capacity classes of the Thermo series.
These are identified by the heating capacity class specifi-
cation as well as colour dots:
• 16 KW: 1 color dot
• 23-35 KW: 2 color dots
• 40 KW: 3 color dots
Nozzle block
pre-heater (optional)
Solenoid valve
Fuel Pump
Screen
O-ring
Color dots for
identification
of the heating
capacity class
The fuel pump can be used in dual-line operation (fuel
supply and return line).
If the heater is operated with
– a long fuel supply line
– check valves in the fuel supply and return line
– a fuel filter in the fuel supply line
– single-line operation
the fuel supply line must be filled prior to first heater
start-up.
Fan motor
Fan wheel
Cap
Splash protection cover
Screen