ULPOWER UL390i, Installation Manual

Page: 21 / 69

Installation Manual
UL POWER
UL390i UL390i S 390i SA
MI 390A01 Revision No: 3 Date: 2014-09-15 Page: 21 of 69
Pump and pre-filter have the same size ending. A fuel hose with 12mm inner diameter should be
used to connect fuel tank with pre-filter and pump to facilitate suction. Simple hose clamps may be
used to tighten the hose as there shouldn't be any pressure build-up in this part or the fuel system.
Verify that the inner diameter of the tube coming out of the fuel tank is not less than 8mm to
ensure sufficient fuel flow to the pump. Also make sure that the position of the suction point in the
fuel tank allows fuel to be sucked out of the tank in every conceivable flight situation or engine will
stop running.
Verify that the inner diameter from the return line is not less than 6 mm.
A bracket to fix pre-filter and fuel pump and a bracket to fix the fine filter are included in the “fuel
connection kit”.
The + and - for the electrical connection is clearly marked. Use the appropriate wiring
(2,5 mm²) together with a 15Amp fuse. A switch can be installed on the dashboard to
provide electrical power to the pump allowing the pilot to manually switch the pump
on/off. Alternately a relay switch (see picture on the right - obtainable from ULPower as
an option) can be placed between the pump and Engine Control Unit (ECU), allowing the
ECU to determine when the pump should start and stop. This feature has been added for ease of use
and extra safety. Once power is supplied to the ECU it will automatically start the pump to build up
pressure for about 1.5 seconds, after which it will shut down the pump (also saving on battery
power) until the pilot engages the starter engine. Once the ECU detects the engine is turning, it
automatically switches on the pump to provide fuel and leaves it on until it detects that the engine
has been stopped. In the event of a crash landing and as a consequence an abrupt engine shutdown,
the ECU will automatically shut off fuel pump to reduce the risk of fire.
Electrical Wiring Diagram
IN : M14 x1.5
OUT : M12 x 1.5