FES Maintenance manual Version 1.12
September 2016
Page 10 of 26
3.2.5 Wirings
FES wiring consists of power, signal and 12V wires, and different types of
connectors.
For power cables we use high quality Betatherm 155 wires with cross section of 35 sqmm.
For signal wires we use high quality tinned and shielded wires. For all 12V circuits we use
aviation grade Spec 55 wires.
On the end of power wires are pressed and soldered suitable cable shoes and
Radsok power connectors. Signal wires, are soldered to multipole DB9 or DB15
connectors, and on other side directly to FCC box electronic circuit board. 12V circuits are
equipped with cables shoes.
-DC/DC converter is used to convert high voltage from FES battery packs, to 12V
which is used to supply instruments, and main contactor. It also charge 12V battery if
installed.
-Main contactor is used to connect and disconnect traction batteries (FES battery
packs) to motor controller. There is installed also precharge resistor.
-Motor controller is used to convert high voltage DC to three phase AC voltage
which goes to motor. It also send RPM and controller temperature by CAN bus to FCU
instrument.
-Ventilators are used to cool down motor controller.
-Power switch (double pole) is used to give 12V power to main contactor, supply to
electronic circuit board in motor controller.
-BMS inside of battery packs is used to balance and to control charging. It can be
connected to PC with a special cable in order to monitor charging process with BMS
Control software. During flight BMS is sending data to FCU instrument, about temperature
of the pack and voltage levels of each cell.
-Shunt is used to measure current from Battery packs.
-LXUI box convert analog measurement of current and voltage to digital signal
which is sent by CAN bus to FCU instrument.
-FCC box have electronic circuit board, where all signal and 12V wires came
together and are spitted to right directions. It consist also a microprocessor for automatic
propeller positioning. There is located also 2A fuse, potentiometer for adjusting of
electronic braking and DB9 female connector for FCU update.
-12V battery is not really required for operation of FES system, but is there mainly
to be able to set other instruments if main battery packs are still charging. Battery should
be equipped with 3A fuse.
-325A power fuse protect the whole system in case of a high power short-circuit.
-Battery packs provide power to the whole FES system
-one 1,kW or optionally two 600W external chargers are used for charging of
Battery packs, one by one or simultaneously in case of two chargers.
-FCU instrument gives information to the pilot about important parameters. There is
also located throttle knob, and 3 bright LEDs in red and green color.
