ESC and motor wiring -- curious

Michael Fenimore

Michael Fenimore

Well-Known Member
OK.
So I'm confused about something.
I watched a video on YT from a couple of years ago. It was about building a 250 quad.
When it got down to wiring the ESCs to the motors, the builder stated that when switching rotation by swapping wires on the ESCs, the 2 outside wires should be the only ones swapped.
Yet, I'm pretty sure that when I swapped mine they weren't the 2 outside wires and it worked fine.
Was his comment/statement just a personal opinion?
Here's what I'm talking about:

E S C <-- crude esc module
A B C <-- pads normal
^^^^^^ Motor is spinning wrong direction
Builder's suggestion
E S C <-- crude esc module
C B A <-- pads (wiring) reversed for opposite rotation

Or can any 2 of the 3 wires be reversed?
o_O

Curious and waiting for other's comments.
 
Michael Fenimore said:
OK.
So I'm confused about something.
I watched a video on YT from a couple of years ago. It was about building a 250 quad.
When it got down to wiring the ESCs to the motors, the builder stated that when switching rotation by swapping wires on the ESCs, the 2 outside wires should be the only ones swapped.
Yet, I'm pretty sure that when I swapped mine they weren't the 2 outside wires and it worked fine.
Was his comment/statement just a personal opinion?
Here's what I'm talking about:

E S C <-- crude esc module
A B C <-- pads normal
^^^^^^ Motor is spinning wrong direction
Builder's suggestion
E S C <-- crude esc module
C B A <-- pads (wiring) reversed for opposite rotation

Or can any 2 of the 3 wires be reversed?
o_O

Curious and waiting for other's comments.
Click to expand...
I think he was making it simpler for newer people, though I think I have heard talk about optimal phase order with bigger biased motors I'm 98% it does not apply here as the phases are all symmetric, and the motors are symmetric with the placement of the coils. Some motors that are directionally biased will have offsets, but the motors that we use for this hobby are not like that.
 
Last edited:
GJH105775 said:
I think he was making it simpler for newer people, though I think I have heard talk about optimal phase order with bigger motors I'm 98% it does not apply here as the phases are all symmetric, and the motors are symmetric with the placement of the coils. Some motors that are directionally biased will have offsets, but the motors that we use for this hobby are not like that.
Click to expand...

That was also my understanding from my college electronics courses GJH105775.
If the driving current were pure DC, then I could see being exact with the wiring.
But since the ESC is essentially creating an alternating cycle (pulse) similar to AC, it shouldn't matter.
Thanks for your input.
 
holtneil said:
If you swap any 2 wires will change direction , I think he just like to change outside wires may be there were easy to get to
Click to expand...

You may be right holtneil.
I know there are many ways to do most anything.
I tend to do things easy for me to understand.
Sometimes they're easy. Sometimes they're not. lol
 
So what the speed controller does is to take a DC voltage of the input an create an approximation of a 3 phase output on the three wires of the output. These three outputs waveforms are spaced out by 120 degrees. So when applied to the winding's of the motor (3-pole for instance) a rotating magnetic field is created. Lets say the field is rotating clockwise around the poles - 123123123123..... - swapping any two wires there are only 3 possible swaps (1 and 3, 1 and 2, 2 and 3) resulting in the field rotating - (321321321321.... or 213213213213... or 132132132132...) as you can see all three result in an opposite rotation of the magnetic field thus causing the motor to spin in the opposite direction.

Some motors dont even differentiate the wires with different colors- my multistars are all black - so you hook them up randomly- if they are spinning correctly you leave them be- if they are running backwards you swap any two. The end result is identical.
 
inductionmotoranimation.gif
 
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