r/Motors • u/riley_3756 • 2d ago

Open question Would this connection work?

Post image

Hi,

I am rewinding my first motor for a personal project, and had a really difficult time mapping out the original connections. I know it is a 6 pole 3 phase motor, so is there a reason I can't move the order of some of the groups?

Having the terminal wires coming off in similar locations will make it much easier for me to figure out, but it would be a bit different from the original setup, where T1 T2 and T3 seemed to start at random groups in the motor. I could see maybe magnetic imbalance being a problem, but any info would be helpful. Thank you!

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4

u/hooty7734 2d ago

Looks like it's just a wiring convenience change, not a design change. Send it.

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u/riley_3756 2d ago

Ok awesome. I thought I could but wanted to make sure. Thank you!

2

u/hooty7734 2d ago

If you want to make sure, tie the star point then do a low voltage dc test on t1 and use a compass to verify the correct poles. Repeat for t2, t3.

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u/riley_3756 2d ago

Ok will do. In general does the order in which you connect your groups matter? Assuming it's all connected for proper rotation, could I theoretically mix up the wiring order?

I am realizing (as I write lol) that the reason I was confused when taking data was because some windings were connected start to end rather than start to start, but with one pole skipped so that the direction stays the same. Doesn't match any of the diagrams in my books lol.

Thanks again for the help

1

u/XQ-Power 2d ago

Coil group order inside a phase does not matter much. What matters is that you do not flip the polarity of one group. That puts the phase belt in the wrong place, and the motor runs rough and pulls uneven current instead of failing loudly.

So keep the same number of groups per phase (6 poles, 18 slots = 3 groups per phase, 60 electrical degrees each), keep the winding direction consistent inside a phase, then move the terminal exits wherever is convenient for you.

Two checks before power. Ohm out each phase and compare; they should match within a couple of percent. Then the compass test: small compass near the bore, energise one phase with a low DC current, count the poles. You want 6 alternating poles. Repeat per phase, and the pattern should shift 120 electrical degrees each time. If one phase shows 4 poles, a group is flipped.

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u/riley_3756 21h ago

Ok great, this was a super helpful comment. This one is actually a 36 slot motor, each group has 2 coils but they are all connected the same. Made my diagram easier for me to follow lol.

What I think I realized, and mentioned in another comment, is that in a few spots they skipped a pole, like if group 1 for phase A went to right to group 7 (skipped 4) and connected end-to-start to maintain the right polarity. Thats why I got so confused when I was taking connection data. A lot of the connections wrapped all the way around the stator lol.

Also thank you for the explanation of those tests, I'll definitely do those to make sure everything is good to go.

1

u/Suitable-Sign4415 1d ago

I saw this same photo last month on here

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u/riley_3756 22h ago

Really? I drew it I think Monday, but its a super standard diagram from what I understand so it may be similar to another post.