sa-200 no arc

admin

I have a sa-200 with no arc. By using the serial number it should be a 1979. This welder sat at a tank farm for a long time and I was told by the welder that it did run and welded fine. Late last year I flashed the exciter fields by plugging in a drill into the 110 outlet and manually spinning the head of the drill. After doing that I had power to the outlet and it did arc but wasn't a real clean arc. Now that winter is over I went to work on it again just to find out that now I have no arc, but I still have power at the 110 outlet. I checked the continuity across the leads and I have NO continuity. I proved that I have no breaks in continuity from the stinger clear into the machine and from the ground clear into the machine, but no continuity across positive and negative. I hope I wrote this well enough to give you an idea of what I got here, I dont know what my next move should be.
Reply:contact lincoln with the code number and they will send you a diagram for your machine.you have 110 volts so we know the exciter is working. The open circuit is a problem. You need to follow the wires from the weld terminals all the way back to the weld brushes.Through the current control.Brushes are under the 5" wide band around the generator. one of sets could be stuck and not making contact. On a machine that has set on long time I would start with the brushes. If no open wires then move to the current control. Clean the brush on the inside. (Big doughnut). good luck
Reply:If you have 110 volts. But no welding at 1500 rpms. the most common cause is the 1. Brushes are bad not seated.2.Shunt coils are shorted to Gnd or have open circuit. 3.Your armature has gone bad. Or you might get lucky and its just a wire ate thru by a mouseBrent
Reply:Ok, some progress was made. I pulled off the flat cover so I could look at the larger comutator. I cleaned it with a comutator stone and then tested for continuity. I can trace good continuity from every other brush back to the + pole. From the + brushes to the copper comutator I have continuity. From the Neg pole I can trace good continuity to every other brush. I HAVE NO CONTINUITY FROM THE NEG BRUSH'S TO THE COPPER COMUTATOR. I dont know if that tells anything. My next step I started the machine and tried to weld. When I tried to strike an arc I now had little spark ( I HAD NONE BEFORE). This is when I noticed that around the large comutator I had allot of arcing. ONLY WHEN I STRUCK AN ARC (GROUNDED OUT TO A WORK PIECE) MY BRUSH'S ARCED ALLOT ON THE COMUTATOR. I do not know which brushes arced. Im thinking this should give some good clues to what I have going on. Any ideas are very much appreciated.
Reply:You found the problem. the brushes are not making contact. Could be worn out.or just stuck. Get your brushes working right and she should jump life.The part number of the brushes is on the brush. a number that starts with a T.Handle the brush holder with care you do not want to break them.
Reply:Make sure your brushes are free in the holder, like ccawgc suggested. once you've assured they are and having already run the stone, you might try the water trick...exciter and commutator both.I got this from AWS forum and this seems to be what your problem probably is. There are several ways to this, one of them involves vinegar. According to the people that are supposed to know, this is the correct way it's done. Your machine, you decide.Cleaning the CommutatorIf you have not done so already, remove the band and inspect each brush to insure that they are seated properly...Using a garden hose, allow a trickle of water to flow over the commutator of the main armature on high idle with no load.*At this time, run your brush seating stone across the surface of the cummutator.*Allow the machine to run for 5-10 minutes.*Turn the water and your machine off and check all of your brushes again.*If the brushes are still not seated, repeat the process.*Once seated, remove the hose and run your machine for another 5-10 minutes to dry.*The commutator will glaze over with a chocolate color and this is what you are looking for.DO NOT CLEAN THE COMMUTATOR AGAIN!*Weld with you machine and see how it performs.If it is still too cold,hot, or not stable, then your RPM's and rack will need to be adjusted.-----------------------------------------------------------------Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.                                         -Cree Indian ProverbSA 200 LincolnVictor Torches
Reply:Turns out all of the brushes were stuck. I pulled all of the brush holders and cleaned them up. After I stuck them back in she welded great. Thank you very much.
Reply:I have a lincoln sa-200-f-163 red face arc welder on trailer. $2200**call 740-464-0056
Reply:Go to this forum http://www.aws.org/cgi-bin/mwf/forum_show.pl  and join. It's free. Scroll down in the forum to "Gear 200". Open it and tell your story. These are the true experts for SA 200s. Kaye Sellon will get to your question in time, maybe tomorrow maybe not, but she will weigh in. There are people here too that are members of this forum, but they haven't seen your problem yet. Have some patience, you will get more answers than you bargained for. Some of these guys are pretty caustic at times, so just try to go with the flow.Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.                                         -Cree Indian ProverbSA 200 LincolnVictor Torches
Reply:Originally Posted by dustc53I have a lincoln sa-200-f-163 red face arc welder on trailer. $2200**call 740-464-0056