Start Your Aircraft Electrical Construction
Follow this aircraft electrical
construction process for success with your kitplane.
Start by deciding on all
electrical components you will
use. You don’t
necessarily have to buy
them yet, but you will need the schematics or wiring diagrams to
can get most of these from the
manufacturer’s web site.
Planning it all out
This is the place to
spend the extra
everything out. The
extra time spent
answering all the questions will save you from cutting extra holes,
wrong wires, or running out of parts before you are finished.
out the schematic
will need to collect
all the aircraft electrical schematics
from everything you are installing.
Vans suggests drawing it on the back of their
schematic. I drew
mine on PowerPoint, so I could make
changes as I added the items. I
must have gone through four or five revisions until I was happy. I didn’t want to have to
keep re-drawing all
the time, so I used the computer.
I drew every wire, switch
electronic device. I
didn’t try to re-draw what I already had on
the schematics from the manufacturer.
For example, I put the power lines from my
through the circuit
breaker, to the switch and to the autopilot.
But I didn’t draw all the wires from the back
autopilot to the
servos, these were clear enough on the manufacturer's drawing.
Here's what I came up with:
will be located
is important to
do this now so you can figure out the lengths of all the wires you will
running. You may
need to build brackets
for some of the aircraft electrical components (as I did
Make sure the component
won’t interfere with
other parts of the plane, is oriented correctly, and has enough support
the isometric view labeled “RV-8 AFT MOUNTED BATTERY CONFIGURATION”
sheet OP-10. I
erased the parts I didn’t
want and used it to help figure out where to route all my wires. For the most part, my
wires run from the front
right firewall where my battery is located, to the circuit breakers on
right console. Then
forward into the
right gear box, across the F-802T L.G. box upper brace, into the left
and to the switches on the throttle quadrant.
From there they run through the left gear box,
cabin cover, through the main wing spar, and back the left side of the
aircraft. Here's my isometric diagram:
If I were doing my
airplane again, I
would wire my instrument panel differently. Read here how I
all aircraft electrical wiring to a Wiring Panel.
that you know where all of your aircraft electrical components are
can measure how long each wire will need to be.
I took the schematic and went one wire at a
time. I measured
how long it
would need to be, and
wrote it down on the schematic next to the wire.
Then I was able to use the chart on page 5-20
of the plans, and the manufacturer’s recommendations, to determine wire
sizes. I marked
these on the schematic
you are ready to buy
all the aircraft electrical
parts and wire you will need. If
have made a comprehensive schematic you can probably get it down to
number of each fastener. I
buying Van's wiring kit ES EWC-KIT and extra parts from either Vans or
Spruce. I did a lot
of looking and price
comparisons, but in the small quantities I was buying, the extra
outweighed the savings.
you know the gauge
and number of wires
running through each bulkhead, you are ready to start drilling holes. I stuck with Van's
suggestions on where to
drill. See bottom
of gear box and aft
end of main spar for the only two difficult spots I had.
used the Vans Nylon Wiring
Conduit inside both wings, through the main spar, and down the
fuselage. For the
smaller holes I used rubber and
plastic grommets, and for the larger holes I used cat tracks.
Before I ran any wires, I
string through the
conduit. Then, when
I was pulling wire, I
taped it and another piece of string to the original string. Then I pulled it all
through. This made
it easy to pull the wire, and also
gave me a new piece of string to pull the next wire.
Time to start
pulling wires and
connecting your aircraft electrical components up.
through the conduit, I suggest pulling the longest wires first, then
up with the shorter ones (see Helpful
Hints for more on Pulling Wires).
pulling the tail light and pitch trim wires and ended with the wing
lights. Use only
good quality ratcheting
crimpers to finish the connectors.
Tracing electrical shorts is a pain, especially if they are
don’t want all your
work ruined by poor quality crimps that fail after a short time. Along the same line, if
the wires aren’t
marked, tracing them is tough. See
Labeling for how I would do it.
use a trickle
charger to test avionics
and other complicated aircraft electrical components.
may ruin the circuits. Use
battery or power supply. Make
sure it is
giving enough power to run the circuit before you decide that the
wired incorrectly. Not
enough power may
lead you to believe something is wired incorrectly.
I thought my power supply was large enough to
run the autopilot servos. When
clicked at me, and didn’t work, I thought I had wired them wrong. I hooked them up to a
battery and voila,
everything was correct.
I checked each circuit as
I wired it,
while I was familiar
with where I was working, which tools fit, and how I had to lie, crawl
to get to it.
process of planning, drawing, measuring, installing, and testing my
aircraft electrical systems worked very well for me.
worked right the first time! I think it will work well for
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