Brushless Alternator

[g-and-h_electric]

The better half wants some of the "useless junk" out of the yard...........

I have a "Coleman Powerstation" standby generator which makes no output voltage. Coleman is no longer "in business" so no support there. I was able to find some manuals online, which are at a minimum giving me schematics and ohm values for the windings.

1) I have rung out the windings and the are all good. If I remember correctly when I got the unit it did work (this was 8 years ago, and it kinda sat in the yard, as I was too lazy to hook it up permanently).
2) I tested the diodes at the end of the rotor, and found them to be open, these have been replaced, each going opposite the other (do they need to be "oriented" a specific direction based upon the engine rotation? I cant tell from the schematic) I have not installed new MOV's across them as of yet.

3) I did replace the capacitors, again no luck.

Anyone have any ideas? I hate just scrap it , as it is a 10kW unit, and would be nice if not here then at a friends house.....


Howard, G and H Electric

 

[hillbilly1]

Did you charge the capacitors? If it’s like my old Coleman 5000 watt, you would have to throw 12 vdc through the outlet momentarily while it was running to charge the field.

 

[drcampbell]

Yes, diodes need to be oriented the right way, but it has nothing to do with engine rotation.

If the diodes are in stud-mount packages, half of them must be anode-to-stud and the other half must be cathode-to-stud. (different part numbers) And each group of three needs to be oriented the same way.

The exciter windings take the place of brushes. The voltage regulator puts a variable amount of current into the stationary exciter field, which is magnetically coupled into the rotating exciter armature. (like a transformer, except one winding is rotating) Power is transferred from the exciter armature to the main field through the diodes, which are mounted on the rotor and rotate with the two windings.

Current in both the exciter field and the main field windings is DC. Usually, residual magnetism is enough to get things started but it might need a little help if it has been dormant for a long time and the residual magnetism has dissipated.

 

[Metallicbeing]

Here is a short Youtube Video on how to Flash your generator. It's for a Briggs & Straton Generator, but the concept is the same. Give it a try...