Paper-ing my Stator: Or... Electricity confuses me

[Roostabunny]

I'll end up with a spare core when all this is through, and based on the lofty claims about the series R/R that's on its way, keeping a spare stator is clearly superfluous.

Seriously though, Steve, I'll end up with at least one core you can have toward buffer inventory.

[Steve]

I'll end up with a spare core when all this is through, and based on the lofty claims about the series R/R that's on its way, keeping a spare stator is clearly superfluous.

Seriously though, Steve, I'll end up with at least one core you can have toward buffer inventory.

Thanks.

I just put a post in the Parts Wanted forum.

.

[eil]

You failed to read my post, which means you failed to grasp the diagnostic capability of the test method. The leg to ground tests at 5K RPM has been established as probably one of the best diagnostic measurement for determining failed stators.

Established by whom? I already conceded that it's not worthless. I just think it has a lot of potential (har) to be misleading to those who can't read and apply circuit diagrams.

Your statement above is also incorrect and can be confirmed with a simple circuit analysis. You can put one short any where an any of the three legs and it will not have any bearing on the VAC outputs. Again draw yourself a circuit.

Don't need to, I have one right here:



If one leg is shorted to ground, and you put one voltmeter lead on that leg, and the other on ground, you will get 0 volts. That's what a short is. If neither of the other two legs are shorted to ground, you will get 80 volts on both, assuming that the stator normally puts out 80 volts for the given conditions.

By the way, I have never seen a voltmeter register "Nonsense", is that a special kind of meter? Could you elaborate on what that means?

I didn't say the voltmeter registered nonsense, I said the reading (i.e., the result) is nonsense. In a working system. Because they're two separate circuits. If you want to check for continuity between two things which should not have continuity, you do that. Not check for voltage. It's a much more direct way to test for the kind of failure you're looking for.

Anywho, I'm excusing myself from the rest of this thread. Nothing we're debating here is helping the OP and besides, life's too short to argue on the Internet.

[tom203]

eil said....
"If you want to check for continuity between two things which should not have continuity, you do that. Not check for voltage. It's a much more direct way to test for the kind of failure you're looking for."

Yes, but when you ohms test, the stator is not producing- no stress on windings, etc. Plus the multimeter is probably using 9 volts maximum to test, whereas the running AC to ground test is more severe- more likely to find a path to ground if one is available.

[posplayr]

Established by whom? I already conceded that it's not worthless. I just think it has a lot of potential (har) to be misleading to those who can't read and apply circuit diagrams.

Don't need to, I have one right here:



If one leg is shorted to ground, and you put one voltmeter lead on that leg, and the other on ground, you will get 0 volts. That's what a short is. If neither of the other two legs are shorted to ground, you will get 80 volts on both, assuming that the stator normally puts out 80 volts for the given conditions.

I didn't say the voltmeter registered nonsense, I said the reading (i.e., the result) is nonsense. In a working system. Because they're two separate circuits. If you want to check for continuity between two things which should not have continuity, you do that. Not check for voltage. It's a much more direct way to test for the kind of failure you're looking for.

Anywho, I'm excusing myself from the rest of this thread. Nothing we're debating here is helping the OP and besides, life's too short to argue on the Internet.

OK here we go.

Griffin has reported that he has used this method for years. It also makes perfect sense. There are also other members here that have been using it Tom has reported the same.

As you stated the stator should be isolated from the engine case. However if there is any contact between the stator and the case (any place except for the ideal neutral and ground) there will be a perceptible portion of the VAC voltage from the stator measurable from the case. It is exactly the error condition that is being detected.

I didn't say the voltmeter registered nonsense, I said the reading (i.e., the result) is nonsense.

You are also correct in saying that a meter does not read nonsense. The meter reads the potential difference between the leads. If the stator is isolated from the stator the leg to case voltage will be zero (not nonsense) and if there is a short to the case in the stator there will be an AC voltage reading. Also not nonsense. It is not nonsense because the meter doesn't know what nonsense is. It measures voltage. If you indicated two points to locate the volt meter leads on that schematic and showed anyplace where there is a short (except the degenerate case) what I'm saying would I hope become clear to you.


And under the stated fault condition there will be voltage present. History (ask Griffin) has reported that this is a very good diagnostic tool; in fact he claims he has never mis diagnosed (That is however probably a stretch) a stator using this technique

If one leg is shorted to ground, and you put one voltmeter lead on that leg, and the other on ground, you will get 0 volts.

I'm not sure how you deduced making this statement?? Of course if tow voltmeter leads are shorted together no matter what you grounded them to 10,000V or ground the voltage is always zero. That should be obvious and completely unrelated to the discussion.

I believe my statement was that you could short the stator anywhere in one place and still measure 80V across any two legs. However at the same time, if the stator has that short you will pick up that voltage between a leg to ground test. That is exactly the point of the test procedure.


The reason that an ohm meter doesn't work is because there is not enough voltage to break down the insulation. An ohm meter is a very poor choice. It only works if there is a hard failure.

[posplayr]

links

http://www.thegsresources.com/_forum/showthread.php?t=174130&highlight=revised+phase

http://www.thegsresources.com/_forum/showthread.php?t=173785&highlight=revised+phase

see pictures of stator failures and how it affects the leg to leg and leg to case measurements.

OK I have two or three 4th of July parties to go to so I'm signing out.

[Killer2600]

any place except for the ideal neutral and ground

I know it's holiday and many people are somewhere from tipsy to flat out wasted but WTF?

Are you trying to tell us that a three phase with neutral power system will produce 0 volts AC between any line and neutral. Better consult with an electrical engineer that works power distribution before you hurt yourself playing with electricity.

[posplayr]

I know it's holiday and many people are somewhere from tipsy to flat out wasted but WTF?

Are you trying to tell us that a three phase with neutral power system will produce 0 volts AC between any line and neutral. Better consult with an electrical engineer that works power distribution before you hurt yourself playing with electricity.

Sorry for being unclear , I do have a degree so if there is anything specific that you want to ask go ahe

[Roostabunny]

You know that scene in the Hobbit where the rock giants are duking it out while the wee hobbits and elves hang on for dear life?

Feeling like a hobbit.

[posplayr]

You know that scene in the Hobbit where the rock giants are duking it out while the wee hobbits and elves hang on for dear life?

Feeling like a hobbit.

So where do you stand now? Are you waiting for the sh775? Is the stator still in the bike? Did you recheck the measurements on the stator but first confirm the meter is working.

[Roostabunny]

So where do you stand now? Are you waiting for the sh775? Is the stator still in the bike? Did you recheck the measurements on the stator but first confirm the meter is working.

Thanks man!

Stator still in the bike, and marginally charging as we thought.

I got a 122VAC measurement from a household outlet, which I took as confirmation that the meter has been reading OK, but I have not then re-checked the readings from the bike. Been tough with family events and incessant rain. I don't have a garage, so wrenching (especially electrical) is both time and weather-dependent.

I've sent my data to Rick's, which the lady who answered the email said she was waiting for a tech to review it so they could try to help. Course, they're all out of the shop from around mid-day on the 3rd till Monday. I won't begrudge them that, but I do hope to hear something early in the week.

I'm also expecting an R-R from Cycle Parts Warehouse - ordered on the 2nd, hopefully arrive this week. I know they've charged my card, so I believe it's shipped.

[posplayr]

OK, back with the full data set...

Quick Test results (VDC):
Key off = 12.9
Key on +10sec = 12.3
1500 RPM = 13.8
2500 RPM = 13.2
5000 RPM = 13.1
Key off = 13.0

If I'm reading the quick test correctly...
- I'm charging
- I should be getting more voltage at 2500 RPM than at 1500

Edit:
So I think I'm still having stator problems, despite the new unit. Possibly related to the 40VAC I'm getting when I measure leg->ground?

I'm guessing that this is still the valid data and if so yes it is low and based on the low Phase A voltage drop data you are not pushing any current. Unfortunately it still points at the stator, even if the data appears inconclusive.

[Killer2600]

Sorry for being unclear , I do have a degree so if there is anything specific that you want to ask go ahe

Nothing I need to ask as I'm self-sufficient on the subject but if you'd like to clarify in what way a wye configured stator with neutral shorted to the engine case is "undetectable"

[posplayr]

Nothing I need to ask as I'm self-sufficient on the subject but if you'd like to clarify in what way a wye configured stator with neutral shorted to the engine case is "undetectable"

Sorry I posted in a hurry and got wrapped up in Eil's degenerate cases. See if you can find it.

[tom203]

Yes, Roostabunny, your pretty stator isn't pushing enough current- at least towards R/R. How about trying a Caltric stator ? last price I saw was $60 including shipping. Basscliff has been using one for a while.