Quote:
Originally Posted by RyanJK
Can I wire these circuits with wires of greater diameter, or with greater gauge (smaller diameter)?
Since we're not using pneumatics and the Bridge and cRIO come with the wires they need, can I just buy 18 AWG wire for everything?
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No, and No.
The wire minimums exist because wires carrying current will heat up. If a 12 AWG wire is safe to use at 40 Amps, a 14 AWG wire (smaller diameter) is not, it will overheat and may become a fire hazard. 18 AWG is right out.
But, a 10 AWG wire has greater current carrying capacity (known as "Ampacity") because it is thicker, so you can use that everywhere (except the battery cables, which must be 6 AWG or larger).
BUT, copper weighs a lot, and is expensive. So teams will often use the smallest ALLOWED wire for their wiring.
BUT, the smallest ALLOWED wire may have more loss (resistance) than you want, so some teams use wires larger than the minimums.
The point is, there is a tradeoff: Ampacity versus Weight versus Cost versus Loss. You MUST always use at least the minimum, but larger can have advantages.
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OK, knowing all that, we use #10 for 40A circuits and the minimum size for all other circuits. So we have rolls of #6, #10, #14, #18 and #22. I think we happen to have some #20, but maybe not. All in both red and black.
We buy the highest strand count wire we can find, so it is very flexible. Lower strand counts (like 7 strand THHN) is very stiff and a pain to work with. Home Depot and Lowe's do not sell wire good for FRC, in my opinion. McMaster, Mouser, and several wire stores online sell good stuff.