Spheros thermo 231, Workshop Manual

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Thermo 230 / 231 / 300 / 301 / 350 2 General Description
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2.2.1 Nozzle block preheater
At extremely low temperatures malfunctions may occur
without a nozzle block preheater.
At a temperature of < 0°C a thermostat activates the
heater cartridge in the nozzle block. The heating period
depends on the heat reflected within the combustion
chamber. Preheating is deactivated when the thermostat
ambient temperature is +8°C.
If the heater is not equipped with a nozzle block preheater
a retrofit is possible.
2.3 Heat Exchanger
IThe heat exchanger transfers the heat generated by
com-bustion to the coolant circuit.
2.4 Combustion Chamber
The fuel/air mix is dispersed in the combustion chamber
for combustion to heat the heat exchanger.
Heat exchanger
Combustion chamber
2.5 Control Unit
The control unit 1572 or 1572D is the central component
to ensure controlled operation and monitoring of
combustion. If the heater has a control unit 1572 installed,
a retrofit of control unit 1572D is possible (see Section 9).
Control Unit 1572
Control Unit 1572D
2.6 Flame Sensor
The flame sensor continuously monitors the flame
condition during operation. The flame sensor is a photo
transistor changing its resistance depending on the flame
intensity. The signals are supplied to the control unit for
processing.
Flame sensor
2.7 Igniter Box with Igniter Electrodes
The igniter box generates the high voltage for igniting the
fuel/air mix by a high voltage ignition spark across the
electrodes.