Jet Central Rabbit KS 100 SE Series, Руководство по эксплуатации и обслуживанию, Страница: 10 / 43

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3.2 Turbine
Jet Central Turbines utilize a design containing a single shaft turbojet with an annular combustor. The
single stage axial flow turbine drives a single stage centrifugal compressor. The shaft is supported by 2
fuel/oil lubricated pre-loaded angular contact bearings. The turbine speed is controlled by the amount of
fuel received from the fuel pump, which is controlled by the SE POWERPACK / ECU.
3.3 Fuel / Oil System
The fuel supply for all Jet Central Turbines requires that the user to pre mixed fuel and oil together.
Internal lubrication is achieved by routing fuel oil mix to an internal T-fitting which routes a portion of the
Fuel/Oil mix to the bearings and the rest is sent to the fuel nozzles located in the combustion chamber. It
is important to filter the fuel and use proper types of fuel and oil in the turbine engine. Without proper
filtering one or more of the injector needles could become clogged, thus affecting the proper running of
the engine.
Use the supplied hangar 9 fuel filter between the fuel pump and the turbine; this will help insure that the
oil flow reducer will not be clogged. Failure to use this filter can damage the turbine by reducing the flow
of fuel/oil to the rear bearing! See section 7 for fuel and oil recommendations.
3.4 Kero Start System
The initial start sequence of the turbine utilizes the main fuel source (Kerosene / Jet A / Diesel). This
system uses the fuel pump and solenoid valves located within the POWERPACK module to deliver the
fuel to the combustion chamber, the ceramic igniter located internally within the turbine is powered
momentary to initiate ignition.
When the start command is received by the POWERPACK / ECU there will be an igniter preheat time
delay, after which the starter will turn the turbine to preset RPM before the Kero Start solenoid valve will
modulate, at this time the start fuel will ignite in the combustion chamber resulting in a temperature rise
detected from the EGT probe.
During the start sequence i
f the temperature rise and RPM’s are within the pre-programmed values,
“Preheat” and “Switchover point”, then the main fuel solenoid valve will modulate to deliver fuel to the
main burner to bring the engine to the proper idle RPM during the remaining starting ramp. The Kero
solenoid valve is automatically closed w
hen the predetermined RPM is reached during the “Fuel Ramp”
stage
taking the turbine to the “Running” mode, where Turbine control is handed back to the transmitter
throttle control.
Caution : If accidental flooding occurs; steps should be taken to drain the turbine of excess fuel before
attempting the start sequence. Fuel is liquid and, if unburned, will pool inside the turbine and stay there.
The turbine can hold a large quantity of fuel internally and this excess fuel will be ignited on next
successful startup and will be pushed to the exhaust as soon as the airflow inside the turbine is sufficient.
The exhaust will be ignited causing a hot start (in extreme cases a large fireball) that will not hurt the
turbine, but can destroy the model.