image
Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Question regarding Choosing Wire Thickness

  1. #1
    Navigator jckmcgraw's Avatar
    Join Date
    May 2014
    Location
    California
    Posts
    26

    Question regarding Choosing Wire Thickness

    Hi Everybody,

    I have a Turnigy 2s 3300mAh, and I want to throw a JST connector on it to easily connect it to the TBS Core PNP25. My flying wing doesn't exceed 12A. I have a bunch of JST connectors with 22AWG wire lying around, which unfortunately cannot take 12A. I only need the wire length to be about an inch or less (for ease of soldering to the battery 10AWG wire).

    My question is this: Is it OK to use the 22AWG wire because of the small length being used?

    Thanks,
    Jack

  2. #2
    Navigator
    Join Date
    May 2013
    Posts
    285
    Quote Originally Posted by jckmcgraw View Post
    Hi Everybody,

    I have a Turnigy 2s 3300mAh, and I want to throw a JST connector on it to easily connect it to the TBS Core PNP25. My flying wing doesn't exceed 12A. I have a bunch of JST connectors with 22AWG wire lying around, which unfortunately cannot take 12A. I only need the wire length to be about an inch or less (for ease of soldering to the battery 10AWG wire).

    My question is this: Is it OK to use the 22AWG wire because of the small length being used?

    Thanks,
    Jack
    You could try an online calculator like this one:
    http://www.solar-wind.co.uk/cable-sizing-DC-cables.html

  3. #3
    Navigator jckmcgraw's Avatar
    Join Date
    May 2014
    Location
    California
    Posts
    26
    Quote Originally Posted by elmtree View Post
    You could try an online calculator like this one:
    http://www.solar-wind.co.uk/cable-sizing-DC-cables.html
    Thanks for the link. According to the calculator I should be fine as long as I keep the length less than 5cm.


  4. #4
    Instructor Pilot Channel 1's Avatar
    Join Date
    Nov 2013
    Location
    Out in the middle of nowhere.
    Posts
    4,821
    Quote Originally Posted by jckmcgraw View Post
    Thanks for the link. According to the calculator I should be fine as long as I keep the length less than 5cm.
    What you are building is called a fuse, I would seriously recommend you do not use a conductor smaller than 16 AWG copper.

    Wayne
    Everybody loves a bunny.

  5. #5
    Navigator jckmcgraw's Avatar
    Join Date
    May 2014
    Location
    California
    Posts
    26
    Quote Originally Posted by Channel 1 View Post
    What you are building is called a fuse, I would seriously recommend you do not use a conductor smaller than 16 AWG copper.

    Wayne
    When I change the length of cable run to 2.5 cm the matched AWG cable size decreases to 25AWG. I understand that when passing current through a smaller wire you can potentially have a voltage drop with the remaining energy turned into heat (a fuse), but according to this calculator it says it can handle it.

    Are you saying 16AWG copper because of the 10AWG wire initially attached to the battery? TBS 2s 3300mAh batteries have 18AWG cable.

    Also, I'm pretty sure that 18AWG is the largest wire that can fit into a JST connector.

    Jack

  6. #6
    Instructor Pilot Channel 1's Avatar
    Join Date
    Nov 2013
    Location
    Out in the middle of nowhere.
    Posts
    4,821
    Quote Originally Posted by jckmcgraw View Post
    When I change the length of cable run to 2.5 cm the matched AWG cable size decreases to 25AWG. I understand that when passing current through a smaller wire you can potentially have a voltage drop with the remaining energy turned into heat (a fuse), but according to this calculator it says it can handle it.
    Jack
    I base my comments on experience and 30+ years working knowledge of electronics, if you have to use 18 because or connector requirements then so be, it but dropping down to 22 or 25 is asking for trouble.

    Wayne
    Everybody loves a bunny.

  7. #7
    Navigator jckmcgraw's Avatar
    Join Date
    May 2014
    Location
    California
    Posts
    26
    Thanks for the input! Sounds like I might be playing with fire right now. I should probably just switch the 2s batteries over to XT60 connectors.

    Jack

  8. #8
    Navigator
    Join Date
    Feb 2014
    Location
    Central Florida
    Posts
    36
    Quote Originally Posted by Channel 1 View Post
    I base my comments on experience and 30+ years working knowledge of electronics, if you have to use 18 because or connector requirements then so be, it but dropping down to 22 or 25 is asking for trouble.
    Wayne
    In this case, he is only looking at powering his TBS Core - which does also supply power to other electronics, but not things like motors. 16ga would be way overkill.

    There are questions that we need to have answered before we can adequately answer his question.

    • Is this for fixed wing or quad? (Quad's don't have flight servos)
    • If it is fixed wing, what is the size? (Larger control surfaces require more power - although this is getting down to splitting hairs)
    • Confirm that @jckmcgraw is using a typical FPV equipment (safe assumption)
    • Gimbal system? (other than servo tilt/pan)


    Let's look at the power that he actually might be looking at:
    • A 600mW video transmitter typically draws less than 250mA.
    • If he is flying a quad then he doesn't need to factor in servo power
    • Many flight controllers pull their power off the main power leads (very small any ways)
    • Receiver power (other than required by servos is very small)


    His question isn't about running 100 feet of wire, he's only talking about an inch or two. He's talking about maybe a half amp on a quad. 22ga is just fine, everyone runs this on 22ga servo leads all the time.

    That said, I would probably use a heavier gauge for physical strength and soldering ease.

    Paul
    Last edited by Overshoot; 4th August 2016 at 01:58 PM.

  9. #9
    Overshoot unless he is custom wiring it as a standalone the full 12 amps that he said his motor and electronics draw will go through the wire.
    Most of the money I made this year I spent on FPV,the rest I just wasted.

  10. #10
    Instructor Pilot Channel 1's Avatar
    Join Date
    Nov 2013
    Location
    Out in the middle of nowhere.
    Posts
    4,821
    Quote Originally Posted by Overshoot View Post
    His question isn't about running 100 feet of wire, he's only talking about an inch or two. He's talking about maybe a half amp on a quad. 22ga is just fine, everyone runs this on 22ga servo leads all the time.
    Paul
    Doesn't matter, if the amperage is there the gauge must match or else voltage drop sets in and will cause problems, odd intermittent problems which can result in a disaster.

    Wayne
    Everybody loves a bunny.

Page 1 of 2 12 LastLast

Similar Threads

  1. esc ground wire question?
    By doobie in forum RC TECH
    Replies: 7
    Last Post: 2nd June 2016, 06:43 PM
  2. Replies: 0
    Last Post: 28th March 2016, 01:47 PM
  3. Qav 250 carbon Unibody thickness
    By chad2323 in forum LUMENIER
    Replies: 3
    Last Post: 30th March 2015, 11:46 AM
  4. Dji 30 amp esc bec wire question
    By rdurant in forum Power Regulation / Power Distribution
    Replies: 2
    Last Post: 27th July 2013, 06:30 PM
  5. Dji 30 amp esc bec wire question
    By rdurant in forum Team-Black Sheep
    Replies: 0
    Last Post: 27th July 2013, 12:49 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •