Electric wires AWG specifications

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5469
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Location: PuertoYeruá, Entre Rios, Argentina.
Name: Horacio Berardone
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Electric wires AWG specifications

Post by 5469 »

Hello,

I will update my electric installation with new wires and circuit breakers.
I already got the circuit brakers from A Spruce. And downloaded the electric circuit, that is very simple.
I also have valuable info that Victor and Steve posted about this topic a while ago, answering my original post.
What is missing ?
Just the diameter or AWG number of the required wires.
Are these AWG number published anywhere ?
If not, I will measure the existing ones and verify by calculation that they are correct.
Thanks for your time !
Have a nice week end,
Horacio
Horacio Berardone Bouhébent
LV-NGL 1946 C140 SN 10.260.
Based CLN, Colón, Entre Rios, Argentina.
Formerly 9Q-CKN Based FZAB, NDolo, Kinshasa, Congo.
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6643
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Re: Electric wires AWG specifications

Post by 6643 »

Wire gauge selection is covered in AC43-13.1b. The choice depends on load, length, and whether the load will be left on continuously (like the nav lights) or intermittently (like a flap motor, if we had them). The choice of circuit breaker then depends on the wire gauge you are using, so you may have to revisit your circuit breakers, or use larger than required wires, once you figure all the requirements.
5469
Posts: 83
Joined: Tue May 01, 2018 7:00 am
Location: PuertoYeruá, Entre Rios, Argentina.
Name: Horacio Berardone
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Re: Electric wires AWG specifications

Post by 5469 »

Hi John,

Thanks for pointing me to the right doc. I will download and read it carefully,

Kind regards,
Horacio
Horacio Berardone Bouhébent
LV-NGL 1946 C140 SN 10.260.
Based CLN, Colón, Entre Rios, Argentina.
Formerly 9Q-CKN Based FZAB, NDolo, Kinshasa, Congo.
6896
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Re: Electric wires AWG specifications

Post by 6896 »

I used AC 43.13 1b and made an Excel table to compute the AWG sizes from the charts for each of my major circuits. The attached PDF version of the table may be helpful, which includes the relevant figures from AC43.13 1b, Chapter 11. I haven't finalized my power wiring or circuit breaker layout design yet, but this is where I am headed so far. Note, I have some STCs in the mix for leading edge landing lights, which may be different from other projects. Also, I found that sometimes for long wire runs the minimally acceptable AWG size is driven by the voltage drop requirement (<= 0.5 V) vs. the current carrying requirement.
Attachments
Elec Loads and Wire Sizes Redacted.pdf
(188.47 KiB) Downloaded 564 times
5469
Posts: 83
Joined: Tue May 01, 2018 7:00 am
Location: PuertoYeruá, Entre Rios, Argentina.
Name: Horacio Berardone
Aircraft Type: C140
Occupation-Interests: Civil Engineering, Cattle breeding.
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Re: Electric wires AWG specifications

Post by 5469 »

Hello

Is time to update my electric installation, almost all cables, except feeders to radio, transponder and intercom, are original and tagged.

I have AC 43.13 1b plus this excellent document:
Elec Loads and Wire Sizes Redacted.pdf

I want to know, if available, the original AWG sizes of the energy source side, reference is Charles Kimball diagram:

Cable 2 from battery to master relay,
Cable 3 from master relay to starter,
Cable 7 from generator (field) to master switch,
Cable 69 from master switch to regulator (field),
Cable 8 from generator (A) to regulator (A),
Cable 10 from regulator (B) to generator fuse,
Cable 12 from starter (A) to AmpèreMeter (-),
Cable 12 from AmpèreMeter (+) to BUSS.

The reason is that if I get smaller sections from calculation that the originally installed, I want to be on the safe side and install not less than original sizes. And I don't want to cut wires to measure because if I do that my 140 will be inoperative many weeks. Aero cables are not easily available in Argentina.


I will take care of the wiring size from BUSS to loads as per AC 43.13 1b and the mentioned pdf document, plus the actual currents from equipment manuals.

Thanks very much !
Horacio
Horacio Berardone Bouhébent
LV-NGL 1946 C140 SN 10.260.
Based CLN, Colón, Entre Rios, Argentina.
Formerly 9Q-CKN Based FZAB, NDolo, Kinshasa, Congo.
V529
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Re: Electric wires AWG specifications

Post by V529 »

Hello Horacio,

You are "partially" in luck.

I do own a set of original wiring prints from Cessna for our aircraft. The unfortunate part is that while I keep all 120/140 library information in one spot in my office, those wiring prints are not there? Hmmm, well, I did move about 3.5 years ago and I remember they were either rolled or folded up and chances are they are in some box.......waiting to be un-packed. (yes 3.5 years later I still have two closets of boxes waiting.........to be discovered. Hmmm, I must not need that stuff too bad.........)

I did turn my "library" inside out and upside down. While I didn't find my wiring prints I did find all sorts of other curios.
Exhibit A. The original "group" the "National Cessna 120/140 Association" membership list from Elmhurst Illinois. Anyone remember those folks? They lasted from about 1973 until about 1976.
Exhibit B. I found the flying game rules typewritten from the Newton Kansas convention............in 1980! (not the more recent one in 2017)
Exhibit C. I found my wiring diagrams from my airplane when I replaced all the wiring.

Now I have a 30 amp alternator, but I did take my wiring direct from Cessna's at the time with the sole exception of your wire 12 & 13 from the starter to ammeter, then from the ammeter to the Buss. My wires are #8. Original wires were smaller(for the 12 or 20 amp generator) I suspect they were either 10 or 12 AWG.
Note: when I re-wired the aircraft I had installed a 20amp generator, but upgraded certain wires because I knew I would be moving to an alternator.

But I'm pretty certain the following wires should be correct. (I would not have gone smaller than original)

Wire 2 from battery to master relay 4 AWG at 14"
Wire 3 from Master to starter 4 AWG at 166"
Wire 7 from generator to master field 16 AWG no length recorded (this wire removed for current install)
Wire 69 from master to regulator 16 AWG no length recorded (this wire removed for current install)
Wire 8 from generator to regulator 10 AWG No length recorded (this may have originally been a 12 AWG)
Wire 10 From Regulator to Gen fuse This wire is a stumper as I don't recall and no longer have it or need it. I would suspect it's a 10AWG or 12 AWG, no idea on length.
Wire 12 From Starter to Ammeter Originally either a 12 or 10 AWG this one is about 76" long
Wire 13 (you did mean 13? correct?) From Ammeter to BUSS 12 or 10 AWG about 14 "
See my note above, I have 8 AWG in these locations due to heavier current from Alternator

I'm fairly certain from memory, all the heavy current carrying wire. (starter and generator back to the Regulator and ammeter then BUSS was all the same size. Originally it was not 8 AWG as I have now, it was 10 or 12. Perhaps someone that still owns a generator could measure theirs?

Hopefully this helps you out. If I ever locate those drawings, I'll email you. If you need wiring, we have it by the roll in the USA.
V529
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Re: Electric wires AWG specifications

Post by V529 »

5469 wrote: Sat Jan 12, 2019 6:08 am Hello,

I will update my electric installation with new wires and circuit breakers.
I already got the circuit brakers from A Spruce. And downloaded the electric circuit, that is very simple.
I also have valuable info that Victor and Steve posted about this topic a while ago, answering my original post.
What is missing ?
Just the diameter or AWG number of the required wires.
Are these AWG number published anywhere ?
If not, I will measure the existing ones and verify by calculation that they are correct.
Thanks for your time !
Have a nice week end,
Horacio
Horacio,
One item that may help you out:
the diameter of the wire for current Mil spec wiring. MIL -W- 22759/16
(this is the internal stranded wire, not the shielding and the internal wiring!!!)

-2= .340"
-4 = .268"
-6 = .212"
-8 = .169"
-10=.112
-12 = .089"
-14 = .069
-16 = .055
-18 = .049
-20 = .039
-22 = .031

Assuming you have your old wiring, you could remove the shielding and measure the strands, at least you'll know what your current wire gage (AWG) is.
5469
Posts: 83
Joined: Tue May 01, 2018 7:00 am
Location: PuertoYeruá, Entre Rios, Argentina.
Name: Horacio Berardone
Aircraft Type: C140
Occupation-Interests: Civil Engineering, Cattle breeding.
Contact:

Re: Electric wires AWG specifications

Post by 5469 »

Did you conserve your old fuses or switched to circuit breakers ?

Thanks very much for your time and valuable help !

Kind regards,
Horacio
Horacio Berardone Bouhébent
LV-NGL 1946 C140 SN 10.260.
Based CLN, Colón, Entre Rios, Argentina.
Formerly 9Q-CKN Based FZAB, NDolo, Kinshasa, Congo.
User avatar
6643
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Joined: Tue May 01, 2018 7:00 am
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Name: John C
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Re: Electric wires AWG specifications

Post by 6643 »

5469 wrote: Thu May 09, 2019 7:01 pm the two cables from master switch to gen and regulator F were shielded. Perhaps this has an advantage in noise emission
Yes. The mechanical voltage regulator switches the field current up and down at a rapid rate. The average value is what determines the voltage output. The switching generates rf interference.
5469
Posts: 83
Joined: Tue May 01, 2018 7:00 am
Location: PuertoYeruá, Entre Rios, Argentina.
Name: Horacio Berardone
Aircraft Type: C140
Occupation-Interests: Civil Engineering, Cattle breeding.
Contact:

Re: Electric wires AWG specifications

Post by 5469 »

529 wrote: Wed May 08, 2019 8:29 pm Perhaps someone that still owns a generator could measure theirs?
Hello,

I still have the Delco Remy 20 Amps generator. I am happy, it works very well. So when I rebuild the electric wiring, I will note the size and the construction types of all removed wires, just to document how the original was in S/N 10.260. It will take some time, but it will be done.

Thanks John for your help !

Have a nice evening !
Horacio
Horacio Berardone Bouhébent
LV-NGL 1946 C140 SN 10.260.
Based CLN, Colón, Entre Rios, Argentina.
Formerly 9Q-CKN Based FZAB, NDolo, Kinshasa, Congo.
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