On 2/27/2010 11:08 PM, Donald wrote: > > Anybody got any fresh ideas?> > > Any idea what voltage it is charging at when it finally comes on line? It could be that the regulator is set for 18 or 20 (or 24!) volts. If so, your battery should be boiling...
Before you do anything I'd suggest testing the battery, checking the wiring between the generator and the regulator and making sure the generator and regulator are both well grounded. The regulator is mounted in rubber and needs a ground, which should be supplied by a metal strap from the regulator frame that contacts one of the mounting screws. There should be a ground strap from a bolt on the engine casing opposite the oil fill (same bolt as the oil fill support but on the other side of the case) to the nearest engine mount bolt where the bolt head contacts the mount. Most generators also have a separate ground terminal. Shielding from the wiring should connect here. I'm unclear on how you are flashing the generator. Here's how I do it. 1) Remove the 3 wires from the regulator. (Mark them first!) Be sure the battery wire does not come in contact with the airframe (ground). 2) Ground the field wire coming from the generator to the regulator. 3) Turn on the master switch. Be sure the battery wire does not come in contact with the airframe (ground). 4) Momentarily touch the battery wire to the armature wire 5 times for 3-5 seconds each time. Sparks will fly, but just do it. 5) Turn the master off and reconnect the wires (correctly!) to the regulator. If the generator works properly after this, you're done! If it doesn't, remove the wires from the generator. Connect a jumper from the field terminal to ground. Connect a volt meter from the armature terminal to ground. Start the engine and monitor the volt meter. Voltage should follow RPM and you should reach +13-14 volts by the time you get to 1600 RPM. If this works, the generator is OK. If it is negative, the generator is reverse polarized. Flashing the field should correct this. If neither of the above, remove the jumper from the field terminal and repeat. If you do not get at least 1.6 volts at 1300 RPM the field needs to be flashed, there is an internal problem with the generator, or, if you get a negative voltage, the generator polarity is reversed. Also, I recently heard (here?) of a generator that would not work correctly because the mechanical clearance between the armature and the field coils was too great. Could be... Sometimes problems with the generator coming on line late are caused by excessive resistance in the armature. With all wiring disconnected frm the generator, the armature terminal to ground should be about 0.1 Ohms. Bad brushes, a dirty commutator, or an improper rewind can cause this. FYI, field terminal to armature terminal should be 7-10 Ohms. If all this stuff checks out, the regulator must be bad. -- John Skyport East www.skyportservices.net
