Rotor Overheating

[retiredgentleman]

It hasn't failed. The stator apears ready to fail. The windings are burned and I can feel them moving around when I touch them with my finger. All of this was installed a month or so ago, so I assume it to be under warranty from Hugh's Handbuilt. Awaiting a reply from the man himself. The thing I'm worried about is putting a replacement on that also fails, potentially when I'm in the middle of the Mohave desert. If there's something I can do to prevent that...

after reading it sounds like I'm using about 60 of the available 200 watts. My shunt (shit?) regulator is supposed to convert the other 140 watts to heat. If it doesn't do that, two things may happen.

1) too much voltage will go forward to my components, and fry them. For me this really only is my PAMCO (which is still fine). I'm not too worried about blowing a light bulb, they can handle a wide range of voltage.

2) too much voltage will go back into the stator, causing it to get so hot the sticker and paint literally burns off my rotor, and then the stator burns out.

So, it sounds to me like I either got a bad stator that was destined to die or my regulator was not doing its job, shits were about to hit the fan, and maybe I caught it in the nick of time.

From what I can tell, this cannot be the result of a bad cap. Right? It's job is to smooth out the electrical pulses, my problem is from over voltage.

Thanks!
Adam

ps Please please please don't waste the time of people who came to this thread because the have a similar issue and want to find the solution by talking shit about how I'm a dumb fuck for buying a PMA. Thanks.

You may have simply bought a defective PMA or regulator. Factory defects do happen. When HHB supplies you with a new alternator and regulator, that should be the end of the problem.

I've said this a few times in the past, but its worth while saying it again. We're all driving around on 31+ year old bikes. If you plan on taking long trips into the desert, (or the mountains as I do) a wise biker would install an onboard voltmeter. The voltmeter will give you advance notice of electrical under charging/over charging problems, before you strand yourself, and die of thirst under a thorny cactus.

Once you have a voltmeter on the bike, you can put on some local around town miles, to secure your belief that you have a reliable alternator/regulator, before you hit the road.

Edit: Another simple mod is to space the alternator cover out from the engine case, to allow for some cooling air in and some hot air out.

 

[wherearewe]

I have these two little gadgets. Depends on your setup for using them. One is pretty discreet and allows a hidden install with just an LED showing, the other one is pretty obvious.

http://www.ebay.com/itm/12V-24V-Car...595?pt=LH_DefaultDomain_0&hash=item51c1950813

http://www.ebay.com/itm/NEW-SIGNAL-...Parts_Accessories&hash=item259b667e78&vxp=mtr

 

[OakBehringer]

I've spent the lat few hours getting up to speed on the deep details of a PMA circuit, shunt vs series reg/recs, MOSFET vs SCR shunt components, etc. Very very interesting stuff.

It seems fairly obvious that my reg/rec wasn't doing it's job, which translated to heat in my stator. I'm toying with the idea of going with the CF55402 reg/rec. I can't find a reason not to, other than the $200 price tag to fix a PMA "complete kit" that included a reg/rec of its own. But, you live, you learn. What I want is a solid, dependable setup.

After all the reading I have done today, and comparing that to the seemingly common problems people are having with PMA kits on our forum, I really think the cheap (Chinese?) reg/rec that comes with the kits.

I'll let everyone know what I decide to do, what Hugh says, and how it all works out.

Thanks, Cheers, ride safe.

Adam

 

[figure8]

Please keep this up to date. I just read through this but can't remember specifically if you were having voltage spikes? Or just the over heated stator?

 

[OakBehringer]

Please keep this up to date. I just read through this but can't remember specifically if you were having voltage spikes? Or just the over heated stator?

No symptoms while riding. I noticed the rotor, which lead to the stator, because I took off the side cover to rotate my engine while doing the valves.

 

[scabber]

It might not be a bad idea to check your grounds needed for proper current flow. I usually check by unfastening and cleaning the area of contact at the frame and the wire connector. Hope the replacement parts work better and shit happens.

 

[OakBehringer]

Just to clarify in my original post, I said .6 ohms was a good reading. I was wrong. Hugh said that .6 Ohms across the stator leads is too low. Likely a resistance has built up in the unit, and with that comes heat which will further damage the stator.

HHB has requested that I send the PMA kit back for testing and warranty. Looks like it will be a while before I'm back on the road

At least there's a warranty. I'll keep everyone up to date as I work on all this.

 

[XStretchified650]

I have the same toasty issue with my PMA so I'll be watching this thread.

Bumping it for now and I'll be back with details later.

XStrechified

 

[ChewsVolt]

Double bump. Have you received a new unit and installed? I just had the same problem with an eBay purchase stator and rectifier combo. Curious how yours pans out

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[XStretchified650]

The issues I had with the PMA overheating are all resolved.

I think that this discussion got spread out over a couple of threads. Mine was overheating due to one stator wire's solder connection at the windings coming loose. Hugh had a statement about a solder connection issue in a related thread. I pulled mine to investigate and was glad to see that one wire was no longer soldered...I wasn't glad that it came apart but I was glad that the problem was verified.

He sent me a new unit with crimped and soldered connections to the stator wires.

I've got an onboard digital volt meter wired in and the alternator has been working fine. I only have about 300 miles on it but I've had no issues.

I see that Hugh has a five year warrantee on his PMAs now.

XStretchified

 

[ChewsVolt]

Thanks for the update on yours stretchified, good to know it's not something inherently wrong with the PMA setup. I hope my next stator/reg combo lasts more than 100 miles. How does a voltmeter help with the problem? I would assume that would only let you know after a winding has failed and you are no longer producing enough current.
Some have postulated that it's the heat produced by the shunt regulator that is frying insulation. If that's the case it seems the voltmeter would read fine.... until it doesn't. The benefit seems limited to knowing you need to get home on whatever battery power you have left, not so much predicting the failure.
I want to figure out how much current is necessary for how I plan to run the bike. If possible I will look at a lower output stator so not so much juice needs to get dumped off by the reg. And I am not going to buy crappy ebay parts this time there's some cheap stators out there!
FYI I am a total electrical noob so could be making some stupid assumptions here

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