Bubblehead

Bubblehead

Well Known Member
The last time I did some rewiring I labeled wires with a description like "Oil Pressure" or "Fuel Flow Signal." I'm going through a major rewiring as I upgrade the panel in my -8 and thought I should see what others use for a naming scheme.

Is there a code scheme that would result in shorter labels but still make it easy to identify wires? I found one such scheme here:

http://www.tpub.com/content/draftsman/14040/css/14040_84.htm

but it seems a little complicated for my purposes.

Any ideas?
 
One option is to label every plug and socket in the plane P1, P2... and J1, J2... etc.

Pick one end of a cable as the "source" of signals - the choice is not really critical - and label each wire as the plug/socket number followed by the pin number the wire is sourced from (e.g., P7-17) As long as you have a good schematic and/or wire list, future wire tracing will be easy.

Another option I have seen is to generate a 3 letter acronym list and label wires with them to allow longer wire function descriptions with less letters. The acronym thing goes over well with the NASA crowd...:)

A wire may be SWT-PWR-PRM-SOL for "Switched Power (to) Primer Solenoid".

Just be consistent with whichever scheme you pick.
 
I used simple codes such as A for Autoflight, P for Power, V for Avionics etc. So wires get labelled as P1, P2.....P26 etc. Then I generated an Excel table showing the designation, guage, start/end point, purppose, colour and the connnection status (green or red). I don't think I could have kept track without something like that. The wiring diagram is all very well, but only shows the main power distribution. Once you start adding autopilots, EFIS, engine monitors etc it gets - uhmmmm - difficult......:eek:
 
Here's how I did it.

I stole a system I saw used by an avionics shop.

3 segment number (aaa-bb-cc)

aaa = a 2 to 4 alphanumeric that identifies the system (ie STB for strobe or COM1 for primary radio) Use what works for you.

bb = wire number. I started with 01 for power and followed with ground and then signal

cc = wire size such as 20 or 22 etc.

Example for Pitot
PIT-01-14 (from fuse block to switch)
PIT-02-14 (from switch to Pitot)
PIT-03-14 (Pitot to ground)

Example for SL40

COM2-01-20 (Power)
COM2-02-20 (Gnd)
COM2-03-22 (Mic Gnd)
COM2-04-22 (Serial In)
Etc

Of course, these are pretty much useless without a schematic that shows wire numbers and connection locations but together they are great.

I wired all my avionics stack and of course the DC power switching. On test, I found only one wire in the wrong DSUB hole on the XPDR and it was easy to debug and fix with the wire numbers and schematics. ( I was in the hole on the wrong side of the DSUB hole number )

In regards to avionics schematics, when I started, I tried to make one big master avionics schematic. DON'T. Its TOO complicated.

Make a single drawing for each component. The component in question is on the left side of the drawing ( a list of pin numbers with discription
) and the connected pieces are on the right with the wires running left to right. Start with power at the top.

Yes, there will be duplicate information on the multiple drawings but I can assure you that it is simpler to manage and use than a huge "master" with convoluted wires running everywhere on the page.

In regards to wire color, I chose to use yellow for any wire that was hot and not switched such as battery buss items. Red for switched power and black for ground. White for signal.

Good Luck! For me this was about 25% of the overall project time and effort but very rewarding.
 
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Another method

Way back when, as an electronics technician in the Air Force, I worked on an electronic warfare trainer. I think it had about 7000 miles of wire in it. The trainer had 21 cabinets, and within the cabinets were racks, plugs on the back of the racks, and removable cards in various racks. Using a combination of locations, plug/jacks and pins one cable or wire might be labelled as such:

18A4P1-4 12A5J1-2

Translate this to Source Cabinet 18 Rack A4 Plug 1 Pin 4 with Destination Cabinet 12 Rack A5 Jack 1 Pin 2

Not sure in the long run it generates shorter labels but you could think it out.

You could designate sections of the airplane with two letters, such as IP for instrument panel, LW for left wing instead of cabinet numbers, use the J and P for jacks and plugs, and pin numbers. Lets say you were running a wire from the switch panel to the left wingtip light assembly connector. You could label it SPSW3-1 LWP1-1 (Switch Panel Switch 3 Pin 1 to Left Wing Plug 1 Pin 1).

If a switch went from your stick to a component in the instrument panel (audio panel) it could be CSSW4-2 IPAPJ1-5 translated to "control stick switch 4 pin 2 goes to instrument panel audio panel jack 1 pin 5.

Don
 
Great thread!!

In a few months I will be removing my instrument panel and all switches and breakers. Then I'll make a new panel for which I am collecting additional instruments. I'll relocate my switches and breakers from the instrument panel to a side panel. There is no schematic for my plane so I'll be making one as I do the rewiring.

Thanks for all the great ideas for identifying wiring!
 
rzbill said:
I stole a system I saw used by an avionics shop.

3 segment number (aaa-bb-cc)

aaa = a 2 to 4 alphanumeric that identifies the system (ie STB for strobe or COM1 for primary radio) Use what works for you.

bb = wire number. I started with 01 for power and followed with ground and then signal

cc = wire size such as 20 or 22 etc.

Example for Pitot
PIT-01-14 (from fuse block to switch)
PIT-02-14 (from switch to Pitot)
PIT-03-14 (Pitot to ground)

Example for SL40

COM2-01-20 (Power)
COM2-02-20 (Gnd)
COM2-03-22 (Mic Gnd)
COM2-04-22 (Serial In)
Etc

Of course, these are pretty much useless without a schematic that shows wire numbers and connection locations but together they are great.

I wired all my avionics stack and of course the DC power switching. On test, I found only one wire in the wrong DSUB hole on the XPDR and it was easy to debug and fix with the wire numbers and schematics. ( I was in the hole on the wrong side of the DSUB hole number )

In regards to avionics schematics, when I started, I tried to make one big master avionics schematic. DON'T. Its TOO complicated.

Make a single drawing for each component. The component in question is on the left side of the drawing ( a list of pin numbers with discription
) and the connected pieces are on the right with the wires running left to right. Start with power at the top.

Yes, there will be duplicate information on the multiple drawings but I can assure you that it is simpler to manage and use than a huge "master" with convoluted wires running everywhere on the page.

In regards to wire color, I chose to use yellow for any wire that was hot and not switched such as battery buss items. Red for switched power and black for ground. White for signal.

Good Luck! For me this was about 25% of the overall project time and effort but very rewarding.
Click to expand...

Bill, is there any real advantage to adding the wire size to the wire label?

If it's on your master schematic/wirelist/spreadsheet that should be good enough.
 
I used a very simple method. Each circuit, such as Transponder, Radios, Fuel system, fuel pump, etc, (I think I had about 15 circuits) was numbered 1 - 15. On the sketches for each complete circuit, I assigned numbers to each wire, 1 to whatever. Each wire was then labled 2 -3 for second circuit, third wire. Lables at each end of the wire.

Each circuit was a complete system so that when it was wired I could test its operation and fix it before forgetting how the wires ran. I established major wire bundle paths and stuck to them, using temporary ties until everything was wired and complete. I then used old fashioned waxed string to tie it all up.

Works great. Did some additions later and was able to use a wire spoon to add some addlitonal wires to the bundles.

Bruce Patton
 
az_gila said:
Bill, is there any real advantage to adding the wire size to the wire label?

If it's on your master schematic/wirelist/spreadsheet that should be good enough.
Click to expand...

That is a reasonable point Gil. I thought about it a few times during labelling but since I started that way (after copying the method) I decided to finish same.

To your point, the nomenclature is most useful during creation of the schematic where wire sizing is being defined by reference to multiple documents. Afterwards the schematic is the reference document used in the shop.

The only reasons I can fathom for printing wire size on the label is dogmatic matching of what is on the schematic and ease of reading wire size at a later date. I certainly am getting to the point that I need a magnifying glass and good light to see the native printing on aviation wire. :eek:
 
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