sa 250 d problem

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hey guys i just bought a sa 250d with the perk diesel, its a 89 model. it runs awesome and starts within 2 seconds. the problem im having is that when i start it up it wont produce any current. after its started if i strike an arc it barley makes little gold sparks off the end of the rod, and also it wont put out any power out of the 110 receptacal. but if i start it and leave it at high idle setting for 5 minutes then it welds great and puts out 110?? whhats up with that? is that normal for it to have to run for 5 minutes after being cold to start putting out power? i can kill it and start back in a few minutes and puts out the power, but if it sits for 20 or 30 minutes i have to let it run at high idle for a solid 5 minutes before i can start welding with it, and the auto idle works then. any help will be awsome!!! thanks, Nick
Reply:Nick,The common element to both generator and weld output is the exciter current circuit that includes the AC-to-DC bridge rectifier and the fuse located on the inside of the front panel.AC "field feedback" voltage from the generator stator exciter output leads (yellow wires) is rectified to DC by the bridge rectifier which then goes to the weld generator shunt filed coils and regulated by the Fine Current rheostat (blue & brown wires).  This same rectified DC voltage is also applied to the rotor brushes to provide Auxiliary AC output.Seeing as the unit will eventually produce output, it can be presumed the residual magnetism that provides initial field flashing is present.  So, the things to look for are poor connections at the bridge rectifier AC and DC terminals as well as at the rotor brushes leads.  Also check the connections at the 15A field fuse mentioned above and the fuse itself (may be bad but making intermittent contact).  Look for broken wires as well at these points.PM me an email address and I'll forward you some more information.DuaneMM200 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 I'll check that. Also this may help. I've got the rig n the bed of my truck. Today I was welding and noticed that if I picked up the ground clamp while standing on the ground and held it firmly I got a light but uncomfertable shock!!!  So I threw it down and wondered if my bed would strike an arc without the ground clamp. So with the ground clamp on the dirt I strikes my rod on a unpainted spot on my bed and it bumped the idle up and made some sparks, not enough to start a bead but a definatly spark. How is that??? Should I bolt the unit to my bed so it's grounded well or what. Or never had one act like that. I thought this rig was dc?? Dc should not lshock me right?
Reply:By the way my email is my user name at hotmail.com
Reply:I'd be looking for a field exciter circuit wire (on the AC side?) that has rubbed thru the insulation on a metal member.  Could be the cause of the delayed output.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:Where exactly is the field exciter located? And how do I know what's ac or dc?