Jump to content

Generator Motors Too Fast


Curti
 Share

Recommended Posts

Motoring only means, the stator or field coils are good  . Can still have bad armature . There is away to test both if you have more then one wire coming out and bypass regulator or something . Armatures usually short out, not ground out so you'll need to take it to a test shop with growler .or just buy replacement armature if cheap enough .

  Model A sites  or goggle testing 6volt generator have and show testing tractor units on you-tube . If you have more than one wire coming out and all disconnected . I think may cause over speed , sorry forgot exactly .

Edited by ArticiferTom (see edit history)
Link to comment
Share on other sites

Is it a one wire gen or do you have a regulator wired to it ?

 

 I did search your's has more then one wire . There was info on forum Yesterdays Tractors .com on testing generators  separated  from regulators and also the regulators . Good  luck

                                                         tom

Edited by ArticiferTom (see edit history)
Link to comment
Share on other sites

Yes , original was two wire coming out  apparently they change ,adapted these back to one wire to retro on older vehicles . If unit is of vehicle mount in vise and spin with a drill min 700 rpm and I use cupped wire brush in chuck against pulley  with volt meter on case and wire coming out you should see voltage start at about 6-800 rpms depending on set of third brush .

   When you motor it what was ampere if you used charger ?  I think Auto-lite is 3-4 amps .

Link to comment
Share on other sites

I have a generator tester. The first thing I do is motor it.  Then I hook it up to the belt and spin it  CW at the drive end.  No amp output . I built three other generators at the same time, The other three charge fine.

Prior to tearing the gen down I would like to know what I am looking for.  

Link to comment
Share on other sites

 I would think its the circuit with armature in it . You only need field coils to motor . May even be dirty or worn brushes . Can you ohm from brush to brush but you'll have to lift ground wire  or insulate grounded brush and measure to commutator bars .This would be working through band cover .

Edited by ArticiferTom (see edit history)
Link to comment
Share on other sites

If the generator is motoring, it means at least some of the field coils are connected. If motoring faster than expected, it sounds like either the ground or armature brush is not making contact. The adjustment (function) of the third brush is to vary its alignmnet with respect to the ground brush. Its possible the motoring circuit is being completed through the armature brush. If the armature failed (open or short),  I doubt the unit would motor at all. If a field coil shorted internally or against ground, it likely wouldn't produce the field(s) and again wouldn't motor, certainly not fast. If a field coil opened, then no fields would be produced and wouldn't motor at all. That is why I suggest checking the ground or armature brushes first. Ensure the brush springs apply light and even pressure on the commutator. Also look for the ground brush braided wire making good contact to the case and the armature brush wiring possibly grounding out against the case.  

Link to comment
Share on other sites

Ok, I did the growler test on the armature, all is well there. Then installed a new set of Auto-Lite brushes. Tested it with a  6V  It motored at the slow RPM. Spun it on the tester ans viola 17 amps.

 The end result is a good functioning generator.  I suspect maybe the third brush may not have been contacting the armature. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...