What AWG is typically use for 40 amp max? - RC Groups
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Sep 05, 2001, 04:50 AM
Registered User
rcastab's Avatar

What AWG is typically use for 40 amp max?

What size gauge is use for high current application, 40 amps max?
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Sep 05, 2001, 05:37 PM
Electric Airplane Junkie
bhchan's Avatar
For 40 amp, you can use 14-16 ga.

Sep 05, 2001, 07:36 PM
Registered User
schoey's Avatar
I just use 12 gauge for everything, it fits nicely(just!) in sermos connectors, its probably a bit of overkill for my use 0-20A but it isn't expensive.
Sep 06, 2001, 12:42 AM
Recruiter - 60 Amp Club
Ed Lyerly's Avatar
12 or 13. I think the 13 fits the Sermos connectors best.
Sep 06, 2001, 10:37 AM
Registered User
16 gauge wire is too small for 40 amps! I'd go with 12 gauge but 14 gauge would be okay. Here's the resistances in milliohms per foot:

12ga - 1.6
13ga - 2.0
14ga - 2.5
15ga - 3.2
16ga - 4.0

If you have a three inch lead from the battery to the ESC and three inches from the ESC to the motor you have a total of a foot of wire. A foot of 16ga will drop .16 volts at 40 amps but more importantly will dissipate 6.4 watts, that's enough to heat the wiring.

12ga would be .064V and 2.6W, 14ga would be .1V and 4W. The 12ga would weigh .32oz and the 16ga, .12oz.