Alternator slip ring connection?

[billmahy]

Hi all - I've stripped down my 15AC alternator to fit new bearings, brushes and slip ring.

Having read that the slip ring is keyed, so that the rotor wires align to the solder tabs, I didn't take much notice when I pulled the slip ring off the shaft.

I've now found that the slip ring can be rotated 180 degrees. This can change the rotor wires between the centre and outer brushes. I've also now found (after a lot of cleaning) that the rotor wires have a red or white sleeve. The white wire is on the outside of the winding (5mm further away from the rotor shaft than the red wire).

My question is: does it matter which colour rotor wire is soldered to the centre, or to the outer, slip ring tab?

The first pic is positioned with white sleeved wire to centre contact. Second pic is white sleeved wire positioned to outer contact.

[Lebro]

Having given it a bit of thought, I can't see that it matters which way round the wires are connected. All they do is magnetise the rotor. Reversing them would reverse the magnetic direction, but since it is spinning that does not matter. The keyway is probably to stop the slip rings twisting the wires off.

Bob

[ed_h]

Agree with Bob.  I can't see what difference it would make.  It's a rotating field.

Ed

[billmahy]

On 3/14/2022 at 10:12 PM, Lebro said:

Having given it a bit of thought, I can't see that it matters which way round the wires are connected. All they do is magnetise the rotor. Reversing them would reverse the magnetic direction, but since it is spinning that does not matter. The keyway is probably to stop the slip rings twisting the wires off.

Bob

Thanks Bob - I didn't want to re-assemble it all and then find I had them reversed.

[billmahy]

23 hours ago, ed_h said:

Agree with Bob.  I can't see what difference it would make.  It's a rotating field.

Ed

Thanks Ed - I read your excellent article about restoring your alternator before I started. That helped me a lot.