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Jan 30, 2013, 12:38 PM
Registered User
This is excellent, ive got 2 axi goldline motors running on 12 amp speed controllers that have 20awg wires on them, so should i get the same to connect to the battery which is a 3s 20 battery? My reasoning is that the 20c is split between the two motors which shouldnt draw more the 10amps according to the manual. Any oppinions would be great before i order so 20awg.
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Jan 31, 2013, 06:26 AM
Registered User
Here is the chart with all the information you need. These are the specifications of the wire that we supply our customers, both RC and commercial.

A few items to note:

a). Most times when customers buy wire, the supplier does not list the strand count. This is important to the amount of amps that can be drawn as well as the flexibility of the wire. The chart shows the strand count for .08 and .06 wire.

b). The chart is based off of tinned copper wire. Cheap wire is not made from copper, but rather brass or aluminum. Again the consumer would not know this information as the supplier does not reveal this.

c). Voltage is not relevant for our use in RC as the wire is designed nominal voltage of 600V and tested at 2000V.

d). Limitation in amp draw of the wire does not account for any limitations on the attached connector. As an example, 20 AWG wire is good for up to almost 9 amps, but the JST/BEC connector is limited to 5-6 amps.
Jan 31, 2013, 09:06 AM
Registered User
Cool, so pure copper with silicone shroud resistant to 200 degrees C would take more amps than tinned copper? I've had a look again at the motor manuals which has a maximum current draw of 8 amps each (two motors), plus the micro servo's I have, should be alright. on the turnigy 850mah 2 cell 25-35c they use 20awg, cable length of the entire setup is a factor, shorter the better, but don't chop the motor wires!
Apr 01, 2014, 11:13 PM
Registered User
Yash....'s Avatar
Hello guys i am using two esc 60a each for edf which will draw 45 amps each with one battery 2200mah 4s 35-75c is 14 awg enough or any other gauge will be required

Regards
Yash
Apr 03, 2014, 06:53 PM
Registered User
Quote:
Originally Posted by Yash....
Hello guys i am using two esc 60a each for edf which will draw 45 amps each with one battery 2200mah 4s 35-75c is 14 awg enough or any other gauge will be required

Regards
Yash
You might want to re-think the battery if you actually will be drawing 90A from it, a 35C 2.2Ah pack is only rated for 77A and if that is a turnighy nano-tech even the base rating is rather overstated.

14AWG is not enough if that load is going to last any significant length of time, 10 would probably be better if that 90A is for more than a few seconds at a time IMO.
Apr 03, 2014, 11:35 PM
Registered User
Yash....'s Avatar
Thank you for the suggestion
But sir i haven't ordered yet and should i order turnigy nano tech 2200 45-90c as before i was ordering 35-70c nanotech and esc to battery length will approx 100mm max for each esc so on this basis recommend me the wire gauge

Regards
Yash
Oct 02, 2014, 12:46 PM
Registered User
WimH's Avatar
amps versus weight in a flying model :
https://www.rcgroups.com/forums/show...62&postcount=5
Oct 02, 2014, 02:45 PM
Registered User
Besides the usual considerations for wire size, as mentioned above.
High currents induce IR drop in the wires. So, even if the wires don't overheat, a smaller than ideal
wire size can reduce the power available to an electric motor or even servos.
Just saying!
Jan 11, 2016, 04:52 AM
I'm probably not a potato!
prutealex's Avatar
What kind of size wire to 300 amps?
Jan 11, 2016, 12:22 PM
Registered User
How long of a run? How much voltage drop is acceptable?
Jan 11, 2016, 12:29 PM
Registered User
vollrathd's Avatar
Quote:
Originally Posted by prutealex
What kind of size wire to 300 amps?
What is your application?

As an example, we regularly run 80 Amps through #12 wire. But #12 wire is only rated for 20 Amps for house wiring.
Jan 23, 2016, 04:45 PM
I'm probably not a potato!
prutealex's Avatar
Quote:
Originally Posted by James_S
How long of a run? How much voltage drop is acceptable?
Never mind. Ill run 8 awg.
Its rated for 200 amps. So I will run four wires to a Power distribution board So Its 400 A. That gives me 100A of headroom.
Actually The motors might draw 360 amps. But 8AWG still works.
Sep 15, 2016, 08:34 AM
Registered User
I'd like to add to the mix if I may. It doesn't really answer the OP, but may shed some light.

Multiple strands do NOT increase current carrying capacity (except at very high frequency when the skin effect comes into play. ) So for DC voltages, there is no difference. It's the total cross-sectional area that counts. The main reason for using multi-strand cables over wires is flexibility. This is why your house wiring uses wire (cheap and does not move) while your vacuum cleaner has a cable and not a wire. Technically most mains wires would be described as cables since they contain three isolated conductors (multi core), each made of a wire.

The type of conductor covering can affect both flexibility and heat resistance. Retaining heat will have adverse effects. So conductors in a conduit, or bunched with others will have a lower current carrying ability.
The hotter a conductor gets, the less current it can carry. Since the resistance increases with temperature, thus you have a positive feed-back loop that runs away very quickly if the conductor is too resistive (thin)

Multiple strands (in excess of 19) are recommended to be used in areas where the cable will move. Otherwise cables should be clamped. In military installations, crimping is preferred to soldering due to fatigue at the connector/conductor interface. Not suggesting crimped terminals for quads.

You should also note the current limiting ability of your system when selecting a conductor. If you have a 60A source (battery) and an 8A sink (motor) then unless you want to allow for a battery short circuit without damaging the wire, you would size to the motor not the battery. If you have (as a simple example) 4 motors hanging off a distribution board, then each motor will need to be able to draw 8A, while the board needs to draw 32A (this seems to be unclear in some other posts that I have read). One could de-rate to a degree since one could argue that not all motors pull full current at the same time. That's another argument, and one would normally plan for some overhead.

Note that LENGTH is important in this case when considering current carrying capability to prevent voltage sag. For conductor lengths, In most cases we are talking a few 10's of mm on a quad. Consider that that the longer the conductor, the greater the resistance, so in theory, an infinitely short conductor (if that makes sense) can carry an infinite current. So you can over-rate specs to a degree but ere on the side of caution.

Aluminium wire is not very common (mainly used in place of copper during high copper prices). It's inferior in both ductility and current carrying ability, but is much lighter. It was often used in telecoms cables (poor signal quality due to issues with joints) and very difficult to solder. Telecoms use IDC and screw terminals rather than solder joints. And it tends to be wire, not cable.

Some hook-up cable (usually 7 strand) will be steel that is plated with one or more other metals (to make it solderable) and may appear to look like copper. It can be quite springy.

By the way, I see the word "weld" used in place of "solder". These are not interchangeable and very different techniques for joining metals.

While I'm at it. Wire = one strand. Cable = multiple strands or multiple cores

And, those with limited collective nouns, a bunch of wires/cables is actually acceptable (plural of course)

I hope that's helpful
Sep 15, 2016, 09:04 AM
http://www.sgvhumane.org/
cmdl's Avatar
Quote:
Originally Posted by Adub
Multiple strands do NOT increase current carrying capacity (except at very high frequency when the skin effect comes into play. ) So for DC voltages, there is no difference. It's the total cross-sectional area that counts. The main reason for using multi-strand cables over wires is flexibility.
Why wouldn't number of strands increase carrying capacity? They're the number of parallel wires carrying current - more of them means less current per strand, hence increased carrying capacity. No?


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