sa-200 exciter trouble

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i have recently bought a sa-200 and have been haveing exciter trouble. i checked over all the fields and had the armature checked wich have all turned out good. i put in new brushes and tried to flash the exciter.i got it going by placeing a 12v dc current across the brush  terminals and it works fantastic and welds great.however when i shut it down then restart the engine i have to put a current to the exciter to get it going again.i would greatly appreciate some advice on this guys thanks in advance!
Reply:Did you shape the new brushes to the commutator so they make contact along the entire surface of trhe brushes?Weak brush springs.  Put a little more twist to them to apply more pressure.  You can check it out by putting pressure on the brushes while it's running with your fingers to see if it powers up without flashing.  Don't worry, you won't get zapped.Oh yeah - welcome to the forum.Last edited by duaneb55; 07-08-2009 at 10:47 PM.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:thanks i will try shapeing the brushes i had just stuck them in figureing they would seat themselves. i did apply preasure though and that did not help.
Reply:ok well that did not work.is there a wire that feeds the exciter a little current to get it going or does it produce current by itself?
Reply:Produces current by itself from residual field magnetism.How were the exciter fields tested?  Confirm no continuity between all field leads and generator housing.  Should have ~164ohms through exciter field on small flexible wires (not rigid one) with them disconnected from the brush holders.  However, I've had less than 130ohms work.How was the armature tested?    Confirm no continuity between any armature commutator segments and core?  Make sure there are no 'bridges' between any of the commutator segments and free of brush carbon build up.  May need to have a starter/alternator shop stick it on a growler if you haven't already.Assure all connections and eyelets at brush holders are clean including rigid field wire.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:bill at bills welding was a hell of a nice guy and talked me through the testing procecdure ohms were good, tested negitve for shorts in fields as well as armature.took armature to shop and had it growled.i notice output to grinder plug though is only 110-115 dc volts but that could be a poor connection.i think the fields tested 180 ohms though.
Reply:Originally Posted by alty66bill at bills welding was a hell of a nice guy and talked me through the testing procecdure ohms were good, tested negitve for shorts in fields as well as armature.took armature to shop and had it growled.i notice output to grinder plug though is only 110-115 dc volts but that could be a poor connection.i think the fields tested 180 ohms though.
Reply:Originally Posted by alty66. . . I notice output to grinder plug though is only 110-115 dc volts. . .
Reply:ok all was going so well why do i get out of bed somedays.i flashed the exciter one more time and finally it started working properly....oh how short lived that was.i then proceded to tidy up all the wireing,installed nnew battery cables and washed the dam thing down so it was nice and clean.went back to my shop started it up and yup exciter still working good but now i only get a little spark out of my rod and the ******* thing wont jump to the high side when i try to strike a arc....wiskey anyone?
Reply:This followed the bath?  Could be some compromised wire insulation plus water may be shorting to ground.Did the rheostat get wet?  Auxiliary outlet?  Idler board?Check to make sure a wire didn't come off somewhere from the washing either.  If you've got exciter voltage do you have the same voltage at the auxiliary outlet?MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:yes i must say i washed everything thoroughly cause it was full of crud.i did however blow everything dry with air compresser before i started it.i will have to check the auxilary outlet.
Reply:Some time ago someone else had a 200 that quit welding when it got wet from rain.  I don't know what, if anything, he found but it sounded like a 'water bridge' short to ground just as yours does now.Keep us posted.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:will do and thanks for all your advice so far.
Reply:Where are you located?  I see you don't have it listed.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:im in a small town called quill lake in saskatchewan canada
Reply:I guess a little too far for a day trip.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:ok all is finally well in my little world.In my efforts to nicely organize the wireing it seem i had pulled a wire of the switch that feeds the reostat wich only took me 2 hrs of scratching my butt to find.
Reply:GREAT!  Typical electrical troubleshooting - 2 hours of hunting for a 2 minute (in this case 2 second) fix.Thanks for the follow up.  It's good to know the end result.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:since your being so helpful duane i have another question. do i need to run a dc grinder on this thing?is there such a animal?if so can a ac grinder be rewired to run on dc?
Reply:Most brush type motors can run on DC as well as AC and some state so on their labels.edit: Actually, I believe all brush type motors can run on AC or DC.  It's brushless motors that are either AC or DC but not both.  If someone knows differently, please correct me.Last edited by duaneb55; 07-10-2009 at 09:12 PM.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:I was told that if it has a (UL) listing, you can run it on either AC or DC. I have a 1981 lincoln SA200 and all my tools (grinders,drills etc.) and they all have the (UL) listing and I have never burnt any of them yet.
Reply:I've run awhole lot of different tools off my SA, some AC, some both. Just keep the variable speed tools away from it and you'll be fine.Hillbilly Fabworks
Reply:thanks alot guys you have been alot of help it sure is nice to have  a forum like this with so many knowledgable guys on it,