Re-wiring wings

[jepple]

Hello,

I am in the process of re-covering wings for a 140. I am wondering if any one has information on what gauge wire is needed for the landing light and navigation lights and a strobe in the wing tip. I have been looking through manuals and have not found anything on the size of wire needed. Thanks in advance!

[5469]

Hello Jason,

I rewired my C140 by the end of 2019.

You will find useful information here:
viewtopic.php?f=12&t=1137&start=80
http://n140tw.blogspot.com/2014/03/elec ... iring.html
I have more detailed info in the airfield, about exactly what wires AWG we used, but not handy now.

I also attach a pdf with technical details to calculate wire gauges, but you will see that the airplane it has been made for seems to be modified.

Hope this helps,

Kind regards,

[5469]

Hello Jason,

I found the box with the cables that have been removed and marked for reference.

I attach a pic of the terminal that was connected to the NAV Lights Switch.
You can see the 4 cables connected. Two for R and L wing Wheelen lamps, one for tail lamp and one for the two small lamps in the panel.
All cables are old cloth covered. Strands of 7 wires, each 0.40 mm diameter.
The cable had 0.8792 mm2 cross area.
That is very near to a 18 AWG, that has 0.823 mm2.

For my rebuild I selected AWG 16 in this wiring, using MIL-W-22759/16-16 from Aircraft Spruce,

Have a nice day,

[6643]

AC 43.13-1b Chapter 11 contains data for selecting wire sizes. The correct answer depends on current draw, length, and whether the load is intermittent (like a flap or gear motor) or continuous (like a radio, landing light, etc.).

The chart is a little tricky to read if you're not familiar with it. You may want to involve the IA who is going to sign off your recover job.

[a64pilot]

The thing (in my opinion) to remember about wire sizing is that going up a gauge doesn’t hurt, in fact larger wire has less voltage drop and it could be argued that as it ages wire does not get better,it’s likely its internal resistance increases due to corrosion over the years so being slightly larger offsets that, yes I know aircraft wire is tinned, but all metal corrodes just some more than others.
Larger wire is heavier, cost more and can be more difficult to run, but in my opinion slightly larger than min size isn’t a bad thing.

Accidentally being too small can be a bad thing.

When wiring a landing light, do not use the LED amp draw for calculating wire size, the next owner may put in an incandescent not knowing they can’t.

Only AC 43.13 or correct maintenance manual is legit, but just as a comparison this calculator is very useful. just don’t say this is what you used to determine wire size
http://circuitwizard.bluesea.com/#

if you have an Apple device, this App is even better https://apps.apple.com/us/app/circuit-w ... d576865083