Stator rewinding star or delta?

[Guest]

Hi,
I had my stator rewound localy a while back, but when I got it back it seemed to have less turns on it than before. I installed it and measured 40 volts on AC on the 3 phases connected it up and the bike charged.

I have since been told that less windings (with heavier wires) will give a higher current and lower voltage, but produce more heat and require high RPMs above 2000. More windings (thinner wire) will give a higher voltage and lower current.

Stripped down everything to rebuild the bike from sctratch and when I wanted to fit the stator cover noticed that a winding was burned. Tested and found it has low insulation to ground.

The stator papers give a good guide on rewinding your own stator, but the example is for a delta configuration and the GS is a star/WYE/"Y" configuration.
On reading up on this I found that Honda switched some later models (VFR) to a delta wound and found that that Suzuki had both options for the VX800L 90-93. The delta option was for the USA only.
The first question is why?

I have found statements that indicate that a delta configuration gives higher current at lower RPM. Actually stating that at a given low speed it can output 1.732 times more current than the equivalent star winding. The Suzuki test for the delta winding also gives a lower voltage of 65 V AC at 5000 RPM. The reason for this is that two of the windings are actually used in the delta configuration to produce current, one fully and the other partially.

The star/WYE/"Y" configuration that the GS has is stated to give higher voltage at lower RPM. All tests for this give 80V AC at 5000 RPM for the star.
The regulators used seem to be the same regardless of the type of winding configuration.

I was thinking that the reason for the USA only use of delta wound stators is due to the lights always on, thus generating more current at low RPMS in traffic etc.

Has anyone tried a delta wound stator in the GS, meaning maybe inadvertantly following the stator papers that does not state how to connect up a star configuration.

I intend doing the rewind myself and will take pictures and put together some guide, using the method in the stator papers as the base.

Any comments or suggestions will be welcome

[Steve]

I don't have much experience with three-phase wiring, but it appears that in a Y configuration, if you lose one of the windings, you lose voltage on two phases. In a Delta configuration, you would only lose it in one phase.

Maybe I have it backwards?

.

[Matchless]

Can anyone help to confirm any of the details for a stator on a 1980 GS1000G please:

Stator = 18 poles (Confirmed)
Copper wire = #18 AWG
Each pole is wound = 2.5 layers
Each layer on a pole = 13-14 turns (varies slightly)
Each pole = 32 turns (varies slightly)
Turns on all poles = anti clockwise
Poles count = anti clockwise

I want to rewind, but as the stator was done before I cannot rely on it being within spec.
Much appreciated.

[rustybronco]

Matchless,
To address what you first asked, here is some good information on delta Vs. wye stators.

https://lists.cs.wisc.edu/archive/vfr/1999-October/msg00272.shtml

The voltage produced depends on the design. You can design the delta
winding to produce a higher voltage or you can design the wye winding to
produce a higher voltage. To say that one winding will produce more voltage
just because it is a delta is simply wrong.

I think, if you re-wind your stator as a wye stator with a grounded neutral and are matching the gauge wire used, or slightly larger gauge with less turns, you will be fine using a wye winding as opposed the factory delta winding.

I don't know what the voltage output would be without the grounded neutral.

to address

I was thinking that the reason for the USA only use of delta wound stators is due to the lights always on, thus generating more current at low RPMS in traffic etc.

the early GS series bikes took one of the legs out of circuit when the headlight was switched off.

what I would do, if it were me, is to wire the stator "delta" as it was designed, but with a good "quality enameled" heavier gauge wire and properly coat (insulate) the windings with a quality epoxy.
then connect the stator directly to the R/R, connecting a wire to your headlight switch (ignition key switched and fused of course) to replace the one that came from the stator leg.

at what RPM did you measure your 40 VAC?
if it was about 5k RPM's that you obtained this measurement, I think you will be fine.

40 volts rectified is about 20 volts, more than enough for proper regulation.

my opinion of course...

[Matchless]

Dale,
Thanks for the feedback its really appreciated. That link you gave is quite interesting, but they are just trying to cover every possible theoretical issue and not getting down to anything usefull really and only confusing the issue. I saw a statement saying that the Delta configuration gives out higher voltage, but the Suzuki manual actually gives the Delta (USA only) voltage as 65 V AC compared to the 80 V AC for the WYE.
The GS never came out with a Delta stator as far as I know. They only use a WYE with a floating neutral. I am just about ready to start rewinding, just hope someone will pop in and confirm some of the specs as per my last post.

I did remove the headlight phase route a while back and measured the AC voltage then as well, but that was about a year ago before I joined the forum and got hold of more proper information. I may even have a faulty regulator and will look at that as well, but as the bike is not running yet I can only do static and passive tests.
Thanks again and keep well.