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Wire Gauges

Old 08-31-2016, 06:18 PM
  #26  
dereckbc
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Originally Posted by Suprawill1 View Post
I am also looking for 3.5mm bullet motor extension wires, preferably 14awg. It seems that when I find this gauge, they only come in pairs instead of triplets. Don't all these EDF motors have 3 leads?
Most that have 3 wire extensions are 16-18awg. Isn't the motor pulling most of I'm starting to sound like my NEC friend but can someone enlighten me?
What I have tried to tell you, there is no standards or codes they are following. There are two issues with respect to high current levels. Heat and Power Loss both are directly related to the resistance, length, type of metal, and amount of current flowing in the wire. of the wire.

With the length of the wire runs in RC models, you can completely ignore power losses on wiring. The runs are so short the voltage loss is so low is insignificant and you can ignore it.

So how much current can a wire take? How much heat an you tolerate? Well for one you start with the wire insulation. Teflon, Asbestos, and fiberglass insulation can operate up to 400 degrees F. But if you look just about all the RC wiring Insulation is Silicon Rubber which can operate up to 190 degree C or 350 degrees.

Here is the biggie, what is called FUSING CURRENT which is the amount of current it takes to make the wire melt and act like a FUSE. Example on 12 AWG copper is 230 amps. NEC limits 12 AWG to 20 amps, SAE and Marine to 40 amps.
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Old 08-31-2016, 08:21 PM
  #27  
Suprawill1
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Originally Posted by dereckbc View Post
What I have tried to tell you, there is no standards or codes they are following. There are two issues with respect to high current levels. Heat and Power Loss both are directly related to the resistance, length, type of metal, and amount of current flowing in the wire. of the wire.

With the length of the wire runs in RC models, you can completely ignore power losses on wiring. The runs are so short the voltage loss is so low is insignificant and you can ignore it.

So how much current can a wire take? How much heat an you tolerate? Well for one you start with the wire insulation. Teflon, Asbestos, and fiberglass insulation can operate up to 400 degrees F. But if you look just about all the RC wiring Insulation is Silicon Rubber which can operate up to 190 degree C or 350 degrees.

Here is the biggie, what is called FUSING CURRENT which is the amount of current it takes to make the wire melt and act like a FUSE. Example on 12 AWG copper is 230 amps. NEC limits 12 AWG to 20 amps, SAE and Marine to 40 amps.
I appreciate your technical advisory and understand that there are different protocols as far as the NEC to RC codes (or lack thereof) are concerned. My concern isn't quite as far as wire limitations as it is heat sources. I feel that if I make for paths of least resistance, it would let everything else in the circuit breathe easier.
It seems that the biggest electrical concerns in EDF set-ups are motor and battery temps during high current draw situations. If creating a circuit with the least resistive pathways don't help those concerns, then I'll be content with using whatever gauge I'm offered. I just thought that some lines are drawn, even in RC code. (or lack thereof)
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Old 09-01-2016, 05:01 AM
  #28  
Wildflyer
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My flying buddy and I had a strange thing happen with a set of large bullet connectors.

It was a set from Castle Creations, I think they were 5.5 or 6 mm (this was a couple of years ago). we noticed the motor on his 6' size Slick stuttering, during a preflight check.
digging in to the plane, we found the bullet connectors had NO friction when fully inserted.

Somehow the hole in the female connector was larger at the bottom than it was at the entrance, and it matched the shape of the male part.

We didn't trust just bending the pins so we soldered them together. Next flight went perfect, and he believes the connectors were causing problems on the flights before we soldered them
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Old 09-01-2016, 05:21 AM
  #29  
Turner
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Originally Posted by Wildflyer View Post
...we found the bullet connectors had NO friction when fully inserted...
I have seen and reported here this exact same thing with knock-off EC3 connectors. Always test the bullet pairs together before assembling and soldering.
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Old 09-01-2016, 11:56 PM
  #30  
ron_van_sommeren
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Originally Posted by Wildflyer View Post
... Connectors can be the weak link in an electrical system, I have had Deans type connectors melt down ...
Connectors don't care about voltage, they only care about current.

Connector tests, plus pictures
translate...www.elektromodellflug.de/hochstrom-st.-bu..html
Older version of that page, contains some other connectors
translate...www.elektromodellflug.de/oldpage/hochstromst/hochstromstecker.htm
Excellent site, do have a look at the controller, motor, charger, power supply, battery etc. tests.


Connector soldering videos
www.innov8tivedesigns.com
→ resources
→ video classroom
→ soldering videos

Veel soldeertips
S39 / S65 en soldeer-vet/pasta zijn grote bagger!!! - MBF
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Old 09-02-2016, 12:26 AM
  #31  
Suprawill1
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Originally Posted by Wildflyer View Post
My flying buddy and I had a strange thing happen with a set of large bullet connectors.

It was a set from Castle Creations, I think they were 5.5 or 6 mm (this was a couple of years ago). we noticed the motor on his 6' size Slick stuttering, during a preflight check.
digging in to the plane, we found the bullet connectors had NO friction when fully inserted.

Somehow the hole in the female connector was larger at the bottom than it was at the entrance, and it matched the shape of the male part.

We didn't trust just bending the pins so we soldered them together. Next flight went perfect, and he believes the connectors were causing problems on the flights before we soldered them
Just bought the 5.5 bullets for the lipo to ESC connection. These are "so" tight that it's going to be great for more permanent solutions but less convenient for battery connect/disconnect before and after every flight.
I'd rather fight to pull them apart though than have them become loose in flight.
I wonder if in your friends case that they wore over time?
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Old 09-02-2016, 12:30 AM
  #32  
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Got a motor hook-up question for you gurus.
My EDF motor has a wire color code of red, yellow and green. The ESC wires are all black but are labeled W, V and U. What is the cross correlation for the right hook-up?
Attached Images
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Old 09-02-2016, 12:59 AM
  #33  
Turner
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Connect them any way. If the motor turns the wrong direction switch any two.
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Old 09-02-2016, 01:06 AM
  #34  
Suprawill1
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Originally Posted by Turner View Post
Connect them any way. If the motor turns the wrong direction switch any two.
Really?
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Old 09-02-2016, 01:24 AM
  #35  
dereckbc
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Originally Posted by Suprawill1 View Post
Really?
Yes really. If the motor runs reverse, reverse any two wires. Really!. The motors are 3-Phase AC, not DC.
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Old 09-02-2016, 02:37 AM
  #36  
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Oooo kay! Thanks Turner and Dereckbc.
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Old 09-02-2016, 06:08 PM
  #37  
ron_van_sommeren
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Veeery simple animation of a 2-magnetpole inrunner,
an outrunner turned inside out



Switch any two of the three motorwires. But NEVER EVER switch battery wires, will ruin your controller.
Don't forget to remove prop when you're working on your setup.

All three motorwires are equivalent, but not the same. They carry the same voltage and current, albeit delayed by 120 respectively 240.

Have a look at these nice brushless ESCmotor animations (with single step view )
Prettig weekend Ron

Voltages on the three motorwires A, B & C
The 'grass' is PWM chopping, for reducing rpm.

Last edited by ron_van_sommeren; 09-04-2016 at 03:34 AM.
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Old 09-02-2016, 07:14 PM
  #38  
Suprawill1
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Thanks for the motor animations Ron. That helps out with the 3 wire process.
I am however familiar with DC polarity so I would never reverse the power input wires.
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