Big problem! My stator has basically melted all the insulation onto the rotor. Any ideas what would have caused this melt down????
Commiserations.stator has basically melted all the insulation onto the rotor.
😌 Kind of Don to say so but I wouldn't call me an expert, I just know a bit.Stuart is expert on this subject.
Overload, such as additional lighting exceeding amperage rating of the stator
Dead short on stator wiring
None of these.chain rubbed through wire?
The Lucas "generator" on the OP's bike is an alternator. What is "generated" in the stator windings is AC (most of which ends up rectified in the bike's DC system) and is a function of rotor rotation speed, rotor magnetic strength, distance between rotor magnets and stator coil windings, stator coil wire thickness.it's not possible to overload a generator, AC or DC and thus overheat windings as well as sag voltage?
Yes and no.Perhaps this link will better explain possible winding failures, as motor winding failures are generally in common with alternator winding failures.
... Lucas alternators (most motorcycle alternators) are "permanent magnet", there isn't a "power supply" to any permanent-magnet alternator.result of an open in one phase of the power supply to the motor.
As I've posted already, "voltage surge" - caused by the stator disconnecting and the rotor at high rpm - is a possible failure cause but the pictured failure on the windings leaves particular damage on the potting; a I've posted already, OP needs to post images of the damage.failure ... typically caused by contaminants, abrasion, vibration
'Fraid you fundamentally misunderstand the difference between industrial electric motors and the permanent-magnet alternator fitted to the bike of the thread title:-When I managed an industrial electric motor rewind shop,
In post 6, the possibility of an overload
... there is absolutely no way on God's green earth this is possible; while the magnetic strength of the rotor is one criterion affecting the power available to the consumers, the reverse does not exist - the total potential draw of all consumers does not have any connection whatsoever to the magnetic strength of the rotor, nor any of the other criteria that govern the actual power available at any given time.Overload, such as additional lighting exceeding amperage rating of the stator
In the same way as the total potential draw of all consumers does not have any connection whatsoever to the magnetic strength of the rotor, nor can there be any increase if the generated electricity happens to find a path to "ground". The fault here is, potentially, stator AC might get into the DC system unrectified. But that cannot cause stator potting to melt.In post 6, the possibility of [a]
dead short was dismissed.
3. winding grounded
There are two ways of regulating alternator AC - series and shunt:-1. turn to turn
2. shorted coil
AUP Thou Shalt Nots not contravened, no reason you shouldn't post in this forum?If you prefer that I not post in this forum,
The thread has reached post #12 without any more input from the OP. Absent that, I'm not sure there's any point in other contributors arguing?No point in an Irishman and a Scot arguing.
Uh-uh. Bear in mind:-On the Bonnie I replaced stator & rotor on some years ago, one wire from stator had insulation worn through to ground. So direct short to ground.
Mmmm ... same as above, "ground" is just a bit of metal; how were the electrons in the cut wire getting to the other stator wire to make a circuit? Even if the cut wire's conductor was making good electrical contact with the chain, there's oil between the chain links, rollers, sprockets, blah; oil's generally a crap electrical conductor (e.g. oil in oil-filled coils still insulates when the HT windings have thousands of Volts).If the chain cuts wire, it’s a short to ground while conductor is touching chain.
Potentially, worst-case, as the chain was wearing through the conductor strands, the connection between stator and rectifier(?) was being opened and closed repeatedly; each time it was opened, that generated a high-Voltage spike in the stator; rotor spinning at a high-enough speed to raise the spike Voltage above what the stator coils' insulation could handle, the insulation might have burned through between two or more stator coil strands. Otoh, in reality, Lucas tested insulation with 110V, so also might not be any "effects"? 🤞What is the effects to stator?
RM13's and 15's from the late 1950's and early 1960's still 'work' for some people, so they're sixty and more years old. If stator and rotor don't touch, they can't wear.My 6T did the same thing at least 4 times.
First time I thought it was just age
"assembled them ... using feeler gauge to check for correct clearance" - I'm hoping you also did this when you fitted the "cheap Chinese copy"? 🤞replaced stator and rotor, did not last long
thought it was penalty for buying cheap Chinese copy
purchased genuine Triumph stator and rotor, assembled them very carefully using feeler gauge to check for correct clearance which was finally achieved by easing the stator mounting bolt holes. Same result
started using an oil modifier (Moreys) which seemed solve the chain problem except the lacquer in the Moreys quickly built up on the rotor and/or stator and "glued" them together, Result self destructing alternator components,
Mmmm ... how does primary chain wear cause multiple alternator failures, unless the chain cuts through the stator wires or hits either stator or rotor? None of which you've mentioned ...?came up with a theory. I had been experiencing rapid primary chain wear
My problem is not electrical