What is AWG – Wire Gauge
American Wire Gauge (AWG) is a wire gauge standard based on the diameter of the
wire. The diameter of the the wire chosen for RC models and quadcopter is
important, because it determines how much current should go though. As you might
know wider diameter wires (thicker) can handle more current. On AWG scale the
smallest the number is the thicker the cable is for example a 14 AWG wire is
thicker than a 20awg wire.
The higher strand count the wire has, the more current it can handle and it is
more flexible, which is best for RC applications in our case quadcopters and
multicopters in general.
What AWG wire should I choose?
There are two ways to decide.
1. Simply work out what the maximum amp draw is, and look it up in the following
table. This is the continuous max current. The amp requirement can be larger for
our hobby since we choose wire according to peak current (at 100% thorttle, which
don’t normally last more than 10 seconds in most cases)
|AWG||Diameter (mm)||Insulation Thickness (mm)||Overall diameter (mm)||Amps|
A general rule you can safely use is the following
13AWG Wire – 100A
14AWG Wire – 80A
16AWG Wire – 50A
18AWG Wire – 30A
20AWG Wire – 20A
22AWG Wire – 10A
2. Use whatever gauge is on the component you’re using. For example if the
batteries have 14awg wire, use 14awg to go from battery to power distribution. If
the ESCs have 18awg power wires, use the same for your power distribution board.
You can also make your own distribution board with some 18awg wires connected to
the 14awg wires having the connection to the bettery. This way usually works and
provides suitable wires for the components you are using.
Max Currents are different from source to source?
The “max currents” you read off of various tables are often different. They
represent the maximum current for which the heating and losses are below a
specified level, and each industry has different standards and specifications.
For RC quadcopter, the above table should be good enough.
Does Voltage matter?
Voltage is not relevant for our use in RC as the wire is designed nominal voltage
of 600V and tested at 2000V.
The chart above is based off of decent quality copper wire. Cheap, low quality
wire might not be made of copper but brass or aluminium, which could have a bad
effect on the max current it can conduct. The consumers would not know this
unless electrical tests are done on the wires. Therefore, make sure you buy the
wires from trustworthy sellers.
Also Limitation in amp draw of the wire does not account for any limitations on
the attached connector. As an example, 22 AWG wire is good for up to 9 amps, but
the JST/BEC connector is limited to 5-6 amps.