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what gauge wire should I use

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Old 01-18-2014, 07:25 PM
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sportflier62
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Default what gauge wire should I use

New to electric, Have a twin with 2 40 size engines and 2 70 amp esc's.. Want to parallel 2 4s 5000mah 50C batteries using a "Y" connector. This plane will never do aerobatics and will probably not pull over 25C, if that. I have ec5 connectors and plenty of 14 gauge silicone wire. Is this wire size good or do I need something else.
Thanks for any info.
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Old 02-02-2014, 09:52 PM
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chuckk2
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If one C is 5A, 5x25=100A Just say'in 125A(oops!)
14GA is a bit small. EC-5's will take up to about #8 (with some difficulty, and careful attention to the soldering process.)
I'd likely use #8 or no less than #10.
One of my models uses up to 78A (static test) EC-5's and #10wire
The motor can draw up to about 1630W, and steady state rated draw is about 60A.
Paralleling batteries increases the available possible current by 2x.
So, a direct short might result in a very LARGE amount of current flow.
From experience, a failed ESC can cause a spectacular result. (Lots of smoke, fire, etc.)

Last edited by chuckk2; 02-03-2014 at 06:05 PM.
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Old 02-03-2014, 10:04 AM
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First, the math above is wrong. 5X25 = 125 amps. That is very high amperage. Well within the amp capacity of your pack but very close to the 140 combined amps rating of your ESCs. How sure are you of your motor draw? Have you tested it with a watt meter?

Funneling all that amperage through one plug may be convenient but may not be the best idea for sustained loads. You might be better off not running parallel but putting one pack on each motor and running 65 amps per rather than 125 amps out one connector.

In addition, if you isolate the motor/ESC/battery you have redundant power. If you lose a motor/ESC or battery you can continue on one motor. If you parallel everything and have a failure you have the potential to take out everything.

Not saying you are doing anything wrong, just offering some thoughts.

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Old 02-03-2014, 10:20 AM
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Wire Gauge for electric set-up
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Old 02-03-2014, 04:14 PM
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thanks for the info. haven't checked with a meter yet but will have it done by someone at the field. Done a test run and no change in wire/battery temp even after 10 minutes running.
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