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Author Topic: Wire Sizes  (Read 1218 times)

hazmat

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Wire Sizes
« on: June 05, 2010, 04:56:29 PM »

Found this & thought I'd share.
Automotive Single core cables

No.        Strand,   CSA,    Continuous
Strands  Diameter sq.mm      Rating

  7          0.3    (N/k )        4.00 Amps
  9          0.3    (0.7 )        5.75 Amps
14          0.3    (1.0 )        8.75 Amps
21          0.3    (1.5 )      12.50 Amps
28          0.3    (2.0 )      17.50 Amps
35          0.3    (2.5 )      21.75 Amps
44          0.3    (3.0 )      27.50 Amps
56          0.3    (4.0 )      32.00 Amps
65          0.3    (4.5 )      35.00 Amps
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riggers24

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Re: Wire Sizes
« Reply #1 on: June 13, 2010, 08:47:46 AM »

Here is a sheet with the AWG vs mm^2
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I will finish the crash tender someday - Still got tooo many toys to play with

malcolmfrary

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Re: Wire Sizes
« Reply #2 on: June 21, 2010, 01:10:53 AM »

Oy veh.
I still tend to work on "that looks thick enough" vs "will that be enough?" vs "what have I got?"
With the relatively short runs on model boats, I feel that we need to split our requirements between very low current (under 100mA), low current (under 1 A), moderate (up to 5A) high (up to 20A) and "should know better" for anything above that, with consideration for likely voltage drop and temperature rise in the length of run.  As long as the wire is thick enough for the current, and thin enough to let the boat float, the ultimate maximum usage is unimportant.  We really do not need to design for the absolute minimum requirement to carry the maximum anticipated theoretical load.
I have found that the wire recovered from scrapped mains appliances supplied fused for 13A is very adequate for everything that I have tried to power in model boats, and the insulation more than enough for anything that I have subjected it to, bearing in mind that I have carefully avoided combustion, either external or infernal.  The wire from lower fused items has always been adequate for more modest requirements.
I do appreciate the finding and sharing of the information, but I do feel the need to point out that model boat requirements tend to fall into narrower bands of requirement than the tables indicate.  As do the automotive trade, if they were to be strictly honest about it.  Look at your car fuse kit.  The wiring fed by any fuse will likely be wired by the next rating above, if not by a common rating of the max on the vehicle to cater for the owner who will insist on his right to put the highest value in there as a more reliable replacement without the litigation following a car fire.  Or a .22 cartridge, if the urban legends are true.  The intermediate values are likely to be unavailable to us ordinary mortals, and, offered a sample, just as unmeasurable.
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"With the right tool, you can break anything" - Garfield
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