Sa 200 troubles

By c_chabun Date 10-15-2017 17:11

Hi all, I bought my first 200 over 20 years ago and it literally welded small inch like a dream. Bead hotpass cap everythingwas too easy with it. It started to puke some oil out the seals so I parked it and bought another one. The next 200 was like work to weld but I plugged away and welded with it. I came across a nice old redface and bought it but same thing I had to work the rod running beads and would get the odd internal undercut. Back when I started I never new about idle and ocv because hell you just put the rod in the stinger and it welded itself. What do pipeliners use for engine rpms and OCV for running beads on small and big bore pipe? I used to stretch 2 -1/8" 6010 rods on a 8" pipe now the best I can do is 2 1/2

By TRowe

Date 10-16-2017 02:53

SA-200 Lincoln welding machines (F-162/163 engines) are set at the factory with the RPM's at 1550 -No Load. At these RPM's the OCV (open circuit voltage) Maximum is 93 ocv.

Over the years I have seen welders wear out a set, or multiple sets, of wrenches trying to tune their machines to "Perfection" and I must admit I was one of them. I have owned several SA-200 machines and can honestly say that none of them welded the same. My approach to a "new" (used) machine (eventually) was to set everything back to "near" factory settings and start there. To do this you may need to purchase the manual(s) for the model and year machine you are using (Lincoln web site). These manuals will help with the engine settings (carburetor, linkages, etc).

Lowering the RPM's (carburetor) will lower the OCV's and vice-versa, but in my opinion, this doesn't allow the engine to operate normally and the manufacturer set it there for a reason. 1550 RPM's turns the generator at optimum performance, according to Lincoln, and by altering the RPM's the generator is not rotating as it was designed. Also, by adjusting the governor to obtain higher or lower OCV's , or higher or lower RPM's, this can cause the engine to under perform or over perform under a load, which is not desired. Keep in mind, that adjusting one thing can sometimes un-adjust another and before you know it you will have worn out that set of wrenches.

If the engine is operating at 1550 RPM's and the OCV's are slightly under 93 (checked a the lugs), I would recommend leaving the machine alone. If it is still not welding as desired, clean the main armature (commentator) using the appropriate cleaners (check with local welding suppliers) and check the main armature brushes. You may want to install new ones just because?! If the RPM's are at 1550 and the OCV is over 93, then the main armature may need to be adjusted. I strongly suggest getting a professional for this task.

These machines are great machines and will last a welders career, if properly maintained and cared for. They are easy to work on (compared to the new age machines) and there is not much that can go wrong with them. However, as I mentioned above, Lincoln set these machines based on their design for optimum performance just as an automobile's engine is set at the factory.

Side Note: Have you thought of changing the main seals on the "good welding machine" to get it back up and running? How bad are they leaking? Front seal or rear seal-or both? Changing them out is not to difficult if your familiar with this sort of thing. Also, it often said "if it ain't leakin, it ain't a Lincoln"! (Haven't seen to many that didn't leak a little)

Hope this gives you some direction

By c_chabun Date 10-18-2017 04:34

I tried playing with the rpms, I played with the OCV. I do know I had the the generator spinning at about 1520-1530 on my old machine but when I tried to drop the rpms down I found that the arc kept cutting out like there was a bad or dirty ground even after rolling the rack to get 93 and 95 ocvs. As for the old girl I just ordered new seals and will change them out for a winter project when I have time. What I'd like to know is what some of these guys rolling the rack are setting the OCVs for bead hotpass and cap for small and big inch pipe? I remember I was on a job rolling pipe with 7018 and threw a dime in the governor to get a little more heat and when I finished and went to run beads on a small inch line I was getting internal undercut until I remembered and pulled the dime out. So I know I had lower OCVs but how low I'm not sure but I do know now I'm running a whole gear lower to get the same heat at factory settings.