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#250008 04/24/09 12:09 am
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Tony B Offline OP
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Hi folks,
Hope you can help me with this one.

T120 1970; I was not content with the power output, so i upgraded the lot: rotor, single phase high output alternator (both Wassell) & Podtronic 200Watt/single phase.

After this upgrade power output was very good: 3-4000 rpm gave 8amp, even with headlight on (55/60W). Below 2500rpm < 0 amp.

However..the alternator was burned. On the sides of each laminel the isolation was charred, so burning spots are not random. Further cracks in the isolation. Debris everywhere
I am convinced the damage is caused from inside-out and not the other way around ... see photo's.
Did not dare to restart to measure voltage output.

Paul Goff (nice bloke!) said he had sold a lot, but never seen a faulty one, and will swap the cooked alternator. I am now waiting for the new one.

some info: Positive frame, 9AH brand new battery (and yes, absolutely correctly connected :-)
15A fuse in neg line, Neg side of POD connected to Ammeter
Harness partly renewed, all connections soldered and all wires checked for continuity & resistance). A lot of days I was soldering and checking...
One single mass point, also connected to engine. Mass continuity everywhere 0 ohm.
Ignition Boyer micro Mk3, unsurpressed plug caps.
Rotor-alternator gap sufficient. Nice centered rotor: no wobbly behaviour.
After the incident the rotor was black, but removable: no damage, no grooves or whatsoever.
I checked and re-checked everything, but I could find nothing idiot.

Not so much info about a fried alternator problem on the web and also little in a search in this forum.

Ever seen such a thing??, any clues how to avoid a second barbeque experience are welcome.

regards, Tony

Some pics:
[Linked Image]
[Linked Image]
[Linked Image]

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Tony -
I usually like fried stators, but only before 10AM and then only with eggs and salsa. laughing


Actually, that's a very tough break. The flaking epoxy is a sign of over-heating, usually caused by no rotor clearance. Usually if it was touching, you'd have one very crispy place in particular. Yours seems to be located neatly at each coil. (The photos are nice but not highly detailed, or maybe I'm just blind.) This indicates to me that you may be placing battery current back on the stator somehow.

Informed guess #2 would be that you reused the old rotor which is actually shot. You should install a rotor-stator SET.

Informed guess #3 would be a bent crank making the stator rub all the way around. Did you move the crank during your clearance check? You have to move the crank several times and keep checking for .007" min at multiple places after each spin. It sounds as if you knew that though.

Informed guess #4 would be a bad DS main bearing allowing the rotor to touch.

Hope this helps! :bigt



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RF Whatley
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IG #2 - he upgraded the lot (rotor, stator, regulator and rectifier)
When you say it gave 8amp at 3-4000 RPM was that into the battery or where? Less than 2500 RPM <0 amp? Why would the output drop off completely with 500 RPM less? What was the voltage on the battery? Could your rectifier be shorted and the battery was discharging through the stator? A new battery might have enough capacity to burn up the stator coils.
If there are not witness marks on the rotor or stator laminations then there probably was no contact.

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Originally Posted by DMadigan
IG #2 - he upgraded the lot (rotor, stator, regulator and rectifier)


And therein lies the problem. What does he mean by "upgrade"?? You suppose a brand new one out of the box, but that may not be the case at all. An "upgrade" could also mean installing a "good used" one from 2 models years newer. Some of these cats think installing a prettier unit is an upgrade. We'll have to see.

confused

Last edited by RF Whatley; 04/24/09 4:32 pm.

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<This indicates to me that you may be placing battery current back on the stator somehow.>

I'd go along with RF on this especially as there is no damage on the rotor (it is not rubbing on the stator) and it is black. There is a warning in the Lucas documentation along the lines of if your rectifier is shot current will flow out of the battery into the stator and (partially) demagnetise the rotor. This might be why it is black. Also blackness and electricity usually means arcing.

Did you manage to measure what voltage was across your battery especially when you had 8 amps flowing?

Maybe the Podtronics is flaky.

Derry.


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Tony B Offline OP
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Gentlemen,
thanks for your relies.

The status (in random order to reply al your answers):
- The rotor, stator and Podtronic are all brand new, so indeed a new SET

- the burning/overheating was indeed near each coil. The damage was done in a 20-min trip. Back home I noticed a strange smell and dense smoke coming from within the prim case...when I saw the mess I was electrified.

- The rotor was readily black, I thought this was because most of the released & burnt isolation got for a while stuck between the rotor-stator gap. BTW there was a lot of black, burnt debris everywhere.
The black rotor coating could be removed with steel wool and very smooth emery paper. No physical damage, looks almost as new.

- the stator laminations were intact, no blackening and no metal pitching. Only damage was the burnt isolation and some cracks in the plastic layer.

- I checked the gap with a 0,2 mm gauge (0.008") while rotating/moving around & checking several spots.

- The engine was started with rotor but without stator and visually inspected for oscillation, but it seemed steady. At such moments I wish I had bought a micro oscillation gauge at the autojumble
In fact, the rotor is stone solid, and when pull the rotor to check for sideplay, I only lift my bike, but I do not notice any movement. So main bearing? Anyhow, I will do a search in this forum how to check for this.

-The 8 amp was seen at the ammeter in the headlight. Max readout of this gauge is 8 Amp, so even possible it was abit more. But on the other hand, how super-reliable are those Lucas ammeters :-)
Below -lets say- 2500rpm the output was around 0 amp (AND with 55W headlight on, remember?). At stationar somewhere between minus 6-8 amp. Unfortunatelly the trip was short, and I live in town (= traffic), so I had no opportunity to check everything in close detail..pitty.

- The battery was brand new, and voltage (engine off) ca 12,5 Volt. I had in mind to check the voltage with engine-on directly after return of my ride. Confronted with the mess in the prim case, I did not dare to do a voltage test anymore with the cooked stator. Should have done a voltage test in advance, but never to old to learn.

So what I see by your reactions (correct me when I am wrong) is a possibility of discharging of the battery through the stator towards the rotor. Reason: rotor-stator gap not OK/fluctuating or faulty Podtronic.

Hmm, nice prospective to fry another alternator in near future.

Claimed output of the Wassell is 190 watt. Headlight,ignit etc consumption would be about 100 Watt, So lets say half of the 190 watt could be available for the battery: which is 7-8 amp (depending you use 12 vs 14,5 volt in the calculation). Amm readout was 8 amp at 3-4K rpm so this energy mass balance looks more-or-less OK to me.

Question1; if there was indeed an arching/and or overheating in the rotor, why would my ammeter still indicate +8 amp? I would say that a lot of energy would be needed for stator havock. If the energy was provided by the battery the ammeter would "see" this power drain.


Question2: If the podmeter is flaky, is there a method to check this?

We will see: but first wait for the new stator, before I can fry another one. The old one is shipped back to the UK.

Please,if you have questions & suggestion/remarks: do not hesitate!

regards, Tony



Tony B #250164 04/24/09 10:12 pm
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..Im thinking 0 amps measured at Batt under 25\3000rpm indicates reg\rec fault?=backup in stator and fry?Or,sudden 8 amps[+?]over 3K-rpms rather Hi for batt to take in?=backup in stator again...but,shouldnt a zener handle excess Amps?..possible faulty zener?..always possible theres a short to be found too...seat pan check?..

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I would get some 10 ohm resistors (~2watt) to put between the new stator and the Podtronics. Turn on the ignition and check the voltage on the stator windings (without the engine running). Any voltage there and the Podtronics has bad rectifier(s).
With the output of the Podtronics solely connected to a resistor load of ~3 ohms (on ceramic core) and running the engine on the battery, measure the voltage on the resistor. It should not go over 14.5 volts. Check on the AC range too to see that the output is DC only. Is the Podtronics mounted on a heat sink? Most regulator/rectifiers need to be.

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It certainly looks like it has had a battery conected across it. I don't think an alternator puts out sufficient power to fry itself in such a manner. I would have the Podtronics examined very carefully.
Perhaps Derry is following this thread and might conduct experiments with his motor setup.

Last edited by andrewinpopayan; 04/25/09 10:43 am.

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Tony B Offline OP
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Sound advice, DMadigan, will invest in a 10omh resistor and check set-up as you described.
Podtronic manual (single phase hi-power #POD1p-hp) http://www.podtronics.net/ claims that no heat sink is needed & that the body does not need to make physical contact with mass. Only a spot in free air (no enclosed area) is needed. I put it directly on the metal of my battery tray, behind the carbs, so more or less: "in the wind".
Tony

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Question1; if there was indeed an arching/and or overheating in the rotor, why would my ammeter still indicate +8 amp? I would say that a lot of energy would be needed for stator havock. If the energy was provided by the battery the ammeter would "see" this power drain.
Question2: If the podmeter is flaky, is there a method to check this?

Q1 who knows Tony, but a lot of energy is stored in a battery. With a decent size battery I have known people to weld with them.

Q2 I know of none unless you have a circuit diagram. But, do you have another bike to try it on, or a good friend who would try it on his? <s>

Perhaps when you get you replacement parts you can try things one step at a time. First fully charge your battery. If nothing else this will allow you to run your bike to make some basic checks. Second run your bike with the alternator disconnected and measure the alternator output.

Ideally you can follow the Triumph manual here and use a 1ohm resistor or if you don't have a resistor just measure the output of your alternator (meter switched to AC) at 3000rpm. With no resistor you will measure over 35V AC.

If this is OK (and I'd be surprised if it wasn't) then connect your alternator to the Podtronics and measure the voltage at your battery. It should read around 12.6V DC, start your bike and the voltage should rise to around 14.5V at a fast tick-over (3000rpm). If it doesn't it looks like a duff Podtronics.

Let us know how you get on.


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Originally Posted by Tony B

Paul Goff (nice bloke!) said he had sold a lot, but never seen a faulty one, and will swap the cooked alternator. I am now waiting for the new one.

some info: Positive frame, 9AH brand new battery (and yes, absolutely correctly connected :-) 15A fuse in neg line, Neg side of POD connected to Ammeter Harness partly renewed, all connections soldered and all wires checked for continuity & resistance). A lot of days I was soldering and checking...

I checked and re-checked everything, but I could find nothing.



Tony -
Time for some self inspection, I think.

I believe the discolored rotor and the reading on the ammeter are all "bunny trials" and merely indicators of a bad problem which are misleading the diagnosis.

Look at the components: new stator, new rotor, new Podtronics rectifier-regulator, new 9AH battery. This is all first class stuff; the kind I would buy for my own bike. Like Paul Goff, I've never seen or heard of a problem from any of these pieces. In fact the Podtronics is pretty much guaranteed for life.

There's only one thing left, and that's the wires connecting it all together. By your admission, the harness is patched back together. I think you either need to take this bike to a shop that specializes in Brit bike electrical systems, or you need to buy a new harness. Considering the cost of labor, the harness will probably be far cheaper, especially considering what the bike will look like after another injection of cash.

In your previous post, you talked about the "ammeter harness". There is simply no such beast, leading me to believe you're not accustomed to doing this type work. That is, you probably can't look at a schematic for your bike and tell me exactly what each wire does. If you can't, that's not a personal fault, but you must admit it's certainly not a positive trait when re-wiring a motorcycle!! laughing

The fuse being on the negative side of the battery is also not desirable. So there are numerous hints that lead me to my conclusion, with no animosity towards you personally.

Friend, given that there are a zillion possible ways to interconnect the 30 or 40 wires in the harness, troubleshooting this issue over the net is going to be improbable and next to impossible.

Sorry for the bad news. :bigt


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Thank you guys for the kind replies,
After some self-reflection and discussions I do think that I have to blame myselves for the rotor-stator gap. I did my best, but after very close inspection and some consideration, I am convinced that is the case. Just stupid me... mad
When the new stator arrives I will check and adjust the gap in all possible ways, and have my work rechecked by/with a friend. And then...I wil check again. Let you know for the final result.

Derry % DMadigan: Thanx: will certainly use your hint/tips how to diagnostic electrical components. Somehow I am convinced it will be needed in near future.... laugh

RF: about your concern about my electrical know-how: I rewired/modified 2 classic Guzzi's (Italians are notorious for %#@$ electrics) and a CB450-Honda from zilch (now: 100% reliable). On top of that: in my spare time I restore electro-mechanical & electronic pinballs, which have 250-500 wires per harness.
Pinballs vs Triump's?; well, for a while they are reliable, but you are always aware of "gremlin problems" which come and go. But if the machine is tip-top (typicall dutch, don't think I have to explain)..: 100% fun... laughing
Tony

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Tony -
Well, best of luck my friend.

:bigt


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<In fact the Podtronics is pretty much guaranteed for life>

So any news Tony?

Derry.


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Hi Derry,
Funny you asked, because this very evening 1st attempt after a long period of no-go. Reluctant starting but everything looked OK. Only tried it at standstill, too late for a ride, better with some daylight.
First impression: positive current(that is: Lucas Ammeter in headlight) when reving >2500 rpm, and 13,8Volt at 3500 rpm at the battery. Can give some more precise analysis when the neighbourhood is not in bed and the bike is a bit roadworthy.

Now, this new start-up was with the fried alternator....kind of re-fried alternator laugh huh?
Remember my problem? Seems a pure mechanical problem (and not a electrical problem as I thought). Rotor movement is a bit eccentric (wobbly), so it would always "hit" some stator lamels, almost as if at random....tried all kind of combination of rotor-stator sets; tapping the stator studs, etc etc but no effect. Guess best way to find out is a deeeep investigation, taking the thing apart, thorough measurements etc etc. Such will take a long time and dutch summers are not that long...hmmm. I want to ride, no long term repair...

Purist Triumph owners & restorators and people with a weak stomach can better not read further: blush
so: what the heck: I took the written-off, fried alternator which Paul had send back (battered appearence, but still OK): shaved some of the problematic lamel areas and combined it with the new rotor. After a lot of stator adaptations and measurements this combination did not kissing each other any more. Fixed the stator damaged isolation with a hard laquer and so far so good! ok,ok very pragmatic - and not a permanent nor delicate solution. When days get shorter & temps get lower I promise to do on a more sound solution than this. Till then the brand new stator will stay just in the box.
Tony



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