second lucas e3l dynamo failure

[DazSeaton]

Hi all,
Replaced my E3L dynamo armature a couple of months ago and its gone again. Anyone come across this before?
My bike is a BSA A10 Super rocket, with boyer micro power electronic ignition and boyer power box dynamo regulator. It is 12V positive frame.
I have tried repolarising it and also testing with a volt meter to no avail. It is deceased (AGAIN). 
Could a faulty regulator cause this?
Darren

[trevinoz]

Darren,
                  It depends on what the failure is.
Have a look at the armature and see if the solder has thrown from the commutator connections.
Was your ammeter constantly showing a high charge rate into the battery?
Is the combined load of the ignition system and lighting  too high?
Recently one of my 12V rewound armatures failed due to thrown solder which was caused by a faulty electronic regulator.
The owner was lucky, he only had to resolder the commutator and the dynamo came back to life.
Replaced the regulator and all is good.

Trev.

[DazSeaton]

Darren,
                  It depends on what the failure is.
Have a look at the armature and see if the solder has thrown from the commutator connections.
Was your ammeter constantly showing a high charge rate into the battery?
Is the combined load of the ignition system and lighting  too high?
Recently one of my 12V rewound armatures failed due to thrown solder which was caused by a faulty electronic regulator.
The owner was lucky, he only had to resolder the commutator and the dynamo came back to life.
Replaced the regulator and all is good.

Trev.

Trev,
Commuter connections look good although a little black. sprayed on some electrical cleaner to no avail.
I did notice a little oil in the dynamo which had leaked from somewhere.
Ammeter reading WAS reading ok. just under +4A at about 3000rpm.
Lights not used recently so dont think its that. Elec ignition is specifically for this setup so shouldn't cause a problem.
Have contacted boyer as I think they offer a testing for £15. Will see what they come back with.
Thanks for you suggestions.
Darren

[trevinoz]

Darren,
                     Have you tried testing the dynamo with the reg disconnected?
The procedure has been well documented here.
Trev.

[DazSeaton]

Darren,
                     Have you tried testing the dynamo with the reg disconnected?
The procedure has been well documented here.
Trev.

no but have disconncted the regulator with the engine running and still no reading on the ammeter.
i will have a look for above. cheers
Darren

[fido]

You can test the dynamo by running it as a motor. Remove the dynamo chain and connect the 2 dynamo terminals together. Run a piece of wire from the battery negative to the joined dynamo terminals.

[duTch]

Fido that works, but is only an indication and not conclusive, as discussed a few weeks ago in another thread. They may 'motor' but not necessarily generate- as Trev will attest.
  I had two gennys, and both motored, but neither generated more than a volt or two, had them growler tested, one had duff armature the other a duff field, so I swapped them round and now have one that generates well (on the bench), and the other's a complete dud(I think).
 cheers for now, duTch

[DazSeaton]

You can test the dynamo by running it as a motor. Remove the dynamo chain and connect the 2 dynamo terminals together. Run a piece of wire from the battery negative to the joined dynamo terminals.

Yes tried this with the first one that failed. it ran as a motor so i ascertained that the field coil was ok. correct me if i'm wrong but i thought it would still run as a motor even though it wont give out any charge.

darren

[DazSeaton]

Fido that works, but is only an indication and not conclusive, as discussed a few weeks ago in another thread. They may 'motor' but not necessarily generate- as Trev will attest.
  I had two gennys, and both motored, but neither generated more than a volt or two, had them growler tested, one had duff armature the other a duff field, so I swapped them round and now have one that generates well (on the bench), and the other's a complete dud(I think).
 cheers for now, duTch

ahh you have confirmed what i suspected.
thanks.
darren

[a101960]

no but have disconncted the regulator with the engine running and still no reading on the ammeter.

Daz,

As others have said, the fact that a dynmo will motor is not a reliable indicator of its ability to charge. I am not sure what you mean by running the engine with the regulator disconected. What you need to do is to disconect the green wire, and the yellow wire from the regulator (F & D) and then join them together. Conect the two joined up wires to either a high wattage lamp or a multi meter, and then run the engine.

John

[Triton Thrasher]

E3L dynamos rewound for 12V have a reputation for fragility, if that's what you have.

[DazSeaton]

E3L dynamos rewound for 12V have a reputation for fragility, if that's what you have.

it is indeed 12v. but its not been rewound. they are made 12v from new.
but i suspect you are right. they are just crap!!!

[DazSeaton]

no but have disconncted the regulator with the engine running and still no reading on the ammeter.

Daz,

As others have said, the fact that a dynmo will motor is not a reliable indicator of its ability to charge. I am not sure what you mean by running the engine with the regulator disconected. What you need to do is to disconect the green wire, and the yellow wire from the regulator (F & D) and then join them together. Conect the two joined up wires to either a high wattage lamp or a multi meter, and then run the engine.

John

John, yes have done this with a 12v multimeter. dead as a dodo. thmy problem is its the second armature in two months.
cheers
Darren

[trevinoz]

Darren,
                I would be having a look at the regulator as well.
The armature shouldn't fail regularly.
Get it tested to see what is actually wrong with the winding, e.g. open circuit or short circuited winding.
I wind with 0.7mm for 12V and 0.8mm for 6V.
If your local winds are done with the same gauge wire, they shouldn't be "fragile", as TT so eloquently puts it.

Trev.
   

[DazSeaton]

Darren,
                I would be having a look at the regulator as well.
The armature shouldn't fail regularly.
Get it tested to see what is actually wrong with the winding, e.g. open circuit or short circuited winding.
I wind with 0.7mm for 12V and 0.8mm for 6V.
If your local winds are done with the same gauge wire, they shouldn't be "fragile", as TT so eloquently puts it.

Trev.
  

Trev,
Out here in the UK you can buy new 12V armatures off the shelf. Dont have to wind them. Although that is most likely the problem.
Darren