Stepper Motor Wire Phases

It’s been a few months of little progress (busy with lots of other things) but I’m finally ready to wire up my 1000mm X-Carve. I’ll be using a G540 mounted inside a control panel - here’s my question:

The NEMA 23 motors have Red, Blue, Green and Black wires. As far as I can tell the Red/Blue are one phase and Green/Black are the other phase. It’s not clear to me which colour (hey I’m Canadian :slight_smile: ) is which part of each phase… For example which part of each phase is the positive and which is the negative?

I’ve searched this forum and searched other places online but every time I think I have an answer I see something with different/conflicting information - typical Internet issues I guess.

The reason I’m asking is that in my configuration I’m planning to have all the connection soldered so swapping wires around later would be frustrating.

Any help much appreciated.


Take a look at this reference and see if that helps:

  1. Take Larry’s advice and learn how to determine the coils. (Color coding, OR simply using a multimeter).

  2. [quote=“ChrisGuerette1, post:1, topic:26907”]
    For example which part of each phase is the positive and which is the negative?
    IMHO This doesn’t matter a whole lot (positive vs negative)… This only effects the direction of the motor. Most software / controllers can flip bits in software to adjust the direction without rewiring.

Since the G540 is just drivers, your software (linuxcnc. Mach3, etc) should be able to do this.

I will be using Mach3 and I realize I can the direction in the software but I’m guessing it is still necessary to wire the positive/negative of each phase the same way…?


The polarity truly does not matter. If your motor spins the wrong way for you just switch ONE pair. Also, some stepper have funky wire color that does not match any chart. Try to turn the motor with no wire connected. Then connect a suspected pair - if it is from the same phase, the motor will be much more difficult to turn.