Electronic Control Unit (ECU)
The Fadec ECU supplied with the engine is custom designed for the Merlin90K engine and must not be changed
for any other, as this may result in improper control of the engine. Your engine has been set up and run with this
ECU at the factory and the settings should be left as default. The ECU plugs into your receiver throttle channel
and is powered from the receiver rechargeable battery. The ECU is pre-programmed and only requires simply
setting to your radio. All ecu connections are color coded and easily identified.
ECU Data Terminal
The data terminal plugs into the ECU via the lead supplied.
The display should be used only for starting and test running.
This socket also doubles as the Computer connection socket.
Do not fly the plane with the display connected as there is a
potential for interference. The function of the buttons is de-
scribed later in the “ECU setup”.
Engine installation: Electrical connections
Temperature Probe (thermocouple)
The engine mounting provides an attachment for the
temperature probe using the two nuts provided. The
temperature probe has been carefully shaped and installed at
the factory to align with the small hole in the exhaust cone.
When connecting the temperature probe plug, be sure to get
the plug in the correct orientation- one wire has a white sleeve
and this should be positioned as indicated on the ECU.
RPM Sensor
The RPM sensor used by the ECU to read the engine RPM
is mounted in the front of the engine, this is underneath the
black cover.
Because it receives the magnetic impulses of the rotor, it is
important to assure that other electrical devices that can
generate magnetic fields (e.g. servo, battery cables, pump etc),
mount at least 100 mm away from the engine.
Both the RPM pickup and thermocouple may need extending
to reach the ECU. A standard good-quality servo extension
can be used there- those for JR radios have the same colour
code and this helps avoid any errors when plugging in.
Power cord
The power for the starter and Glow plug is supplied through a 3 wire twisted lead with MPX connectors. Supplied
length is of 50 cm, if it is necessary to extend it, use 1mm² copper section lead.
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