Lincoln sae300 welding too hot

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Hey new here I saved an old Lincoln sae300 from scrapyard.  I got it running cleaned the commutator and made sure all the brushes were able to move in there holders put a new rheostat on it but when I try to weld it’s like it’s turned up way too hot not sure where to go next any help would be greatly appreciated thanks in advance.

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Reply:it might be running too many rpm's
Reply:Thanks for the reply. I set the rpms to around 1600 which is what the tag said with it pinned in high idle
Reply:I think it might have something to do with this resistor it gets pretty warm. I’m trying to get the wires off now to check it but I don’t know how many ohms it’s supposed to show

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Reply:DAN ,dont"see range selector switch dial? maybe got in high gear?
Reply:I’m not sure the only dials I have on the front are the current control, and the job selector which is the new rheostat. Is there supposed to be something else?
Reply:job selector ,, possible  be in high range? might have put vise gripe  turn to lower range
Reply:I would try one clockwise click on the job sector. Be careful not to get it stuck or set between choices. Use the brail technique to make sure it is fully engaged or if the switch is open in the back, look at the position behind the switch and make sure the contacts are completely engaged in the position you chose.  Sincerely, William McCormickIf I wasn't so.....crazy, I wouldn't try to act normal, and you would be afraid.
Reply:The SAE welders have a rheostat like the SA welders and a reactor that is infinitely adjustable instead of the 4 or 5 “gears” that the SA welders have. I have no idea how to trouble shoot the reactor but hopefully some one here does.
Reply:

Originally Posted by Dan300

ly. I set the rpms to around 1600 which is what the tag said with it pinned in high idle
Reply:I have put a tachometer on there. Like I said I’ve worked on this thing for a while. And by to hot I mean turned all the way down running a 3/32 7018 it’s almost blowing through 3/8 plate and if I try to adjust the dial any it will melt the 7018 about halfway through burning the rod
Reply:Measure your OCV.  Should be around 90 volts at max iirc.  If I remember, the rheo on an SA200 is about 80 ohms. Double check your wiring as you mentioned a recent replacement.  As others have said, lower your gear or job selector.Edit: my rheo measured 65 ohms.  For SA200. Also, I made a crows foot knob for remote rheo adjust. It's a nut with a set screw and a crows foot welded to it.  The crows foot looks like an old lady shoe tho.

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Last edited by Insaneride; 01-18-2021 at 10:58 AM.
Reply:Rheostat should get warm. the control on the left is a reactor. it has a brush arm inside so it has no steps in its adjustment. You have one of two problems, either the reactor is turned to one end or it has been bypassed.Find the code number and call Lincoln see if they can send you the correct diagram for it. Then you can make sure it is wired right.You also might be able to get it your self. Go to Lincoln's web site. under support,select find parts, then enter as guest, enter code number in the box. will take you to the parts page and owner's manual. depending on code number the diagram.The older codes do not have diagrams. you can also search by model name then select a newer code and get a diagram that is close.
Reply:The wiring looks correct to most of the diagrams I’ve found. And my code number is 5514. Idk if this helps but I was attempting to weld with it again earlier and I’ve found that it gets even hotter when you turn the rheostat (job selector) up so I guess that part is working ok. And I made sure the reactor is not turned all the way to the end. Is there a way to test the reactor?
Reply:I think the the dial that says normal electrodes , large electrodes ,etc I think it is on large electrodes turn it to your right { don’t know what size electrode your using } the dial on the right turn it to the right also you have a lot of amps and a lot of voltage where you are learning to use the dial us to weld is a lot of practice that dial on the left isn’t like a sa200 is is a rheostat just like the dial on the right I can’t tell by pictures but looks like your at 300 + amps there
Reply:Ok I think I am getting somewhere now (I hope). So now I figured out that the reactor is doing nothing. I can still weld but anywhere I set it it welds exactly the same. The only thing that changes is when I turn the job selector up or down but no matter what rod I use it’s to hot, for example with job selector turned down I can run a 3/32 7018 and it seems to be welding like 130 or so. So to me that would be pretty good for an 1/8 7018 but when I try to burn one of those it gets to hot for it too. I hope this is all making sense. Pretty much whatever size rod I try to burn it is too hot for it. I appreciate all the replies. And according to the diagrams I can find everything is wired correct. The only thing I’m not sure about is where the wires go inside the generator part everything looks hooked up but I’m just not sure where everything is supposed to go inside there I can’t find a diagram or any info on that part. Also I took the shaft out of the reactor put new brushes on it and cleaned the bore of it. And everything is still the same

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Reply:

Originally Posted by Dan300

Ok I think I am getting somewhere now (I hope). So now I figured out that the reactor is doing nothing. I can still weld but anywhere I set it it welds exactly the same. The only thing that changes is when I turn the job selector up or down but no matter what rod I use itÂ’s to hot, for example with job selector turned down I can run a 3/32 7018 and it seems to be welding like 130 or so. So to me that would be pretty good for an 1/8 7018 but when I try to burn one of those it gets to hot for it too. I hope this is all making sense. Pretty much whatever size rod I try to burn it is too hot for it. I appreciate all the replies. And according to the diagrams I can find everything is wired correct. The only thing IÂ’m not sure about is where the wires go inside the generator part everything looks hooked up but IÂ’m just not sure where everything is supposed to go inside there I canÂ’t find a diagram or any info on that part. Also I took the shaft out of the reactor put new brushes on it and cleaned the bore of it. And everything is still the same
Reply:You are welding with a motor generator so if you can adjust it turn it down some more and forget about the numbers on the dial That machine is old so double check your rpms? Is this machine a 6 cylinder gas motor ? Your gonna find out that numbers on that dial are ballpark at the best your are gonna have to learn to run it by feel. If your running low hydrogen wth it your best luck is gonna be getting it turned to overhead and vertical or special applications. Those old dials are confusing and once you learn to use it you will also learn a lot about ocv and what is does to arc characteristics.
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Originally Posted by 12V71

Just for grins, does this machine have any "mystery" boxes anywhere like possibly it has a CV kit installed for wire feeding?
Reply:You have any big rod like some 3/16 low hydrogen or some 3/16 7024 ? Try running that see what happens also does the engine rpm pull down when you strike an arc ?