Greetings!
Brand new member here. I lurked a bit and this looks like a spot where I might find some sympathetic persons to help me.
I'm not sure I have repaired the wiring correctly on this welder I now own, and so I would love to obtain or at least get a looksee at a wiring schematic for it. It is a Century 230 AC DC (an owners manual would be nice ... Anyone have either item? Or does anyone know where I can find such? Hopefully something online or downloadable? BTW below is background info on me and this welder if anyone wants to be bored by this pathetic want to be/new-be
First of all although I am desirous, and given my longtime serious motorcycle hobby and electrical trade I have a continuous need, I just have never really even learned to weld! It has ever been on my "to do" list and I am always eyeing things like Harbor Freight ads with affordable welders on sale ... which of course I never buy because I can't weld ... a vicious circle.
Now out of nowhere a welder has dropped into my lap for free so I feel the impetus and momentum building to become a beginning welder. I am signing up at local JC at the end of the month and in the mean time I want to see if this welder is worth keeping.
As stated in Subject line it is a Century 230 AC DC of unknown vintage except that it is VERY heavy for it's size and is Made in The USA. It also has with it (apparently) a TIG setup. This is a smaller unit in a box ostensibly to sit on top of the welder? and has cables and sockets so it becomes an extent ion of the welder (again ... apparently?) It is at work now so I can't recall what the name it is labeled as ... but it also was made by Century, and it did state on name tag the it was for use on welders up to 275 amps I believe which s/b fine for this 230?
Anyway back to the Welder itself and my problem. When I had my mechanic buddy Robert at work test the welder for me (Note: Robert just learned to weld last semester so he is no expert by any stretch!)
Robert and I found encouragement to begin with when the welder hummed and it's cooling fan drew plenty of air. Without using the TIG module we plugged in cables and tried her out ... immediately it struck an arc and then stopped... then as we tried various settings AC, DC High and Low and what we found was that only occasionally and on no particular setting it would try to weld for a little bit then it would stop again ... intermittent.
Okay now I want to tell you that I am an electrician so I fearlessly plunged myself into overhauling this welder in search of perhaps a loose connection or failing component. I was no disappointed in that regard as I soon found one really bad junction point where wire terminals had burnt nearly free... loose as a goose and showing evidence of plenty of resultant heat! Also there was one conductor that had apparently burnt all the way free and then welded itself to the edge of an aluminum plate! I also found that the main power switch was binding on repeated on off action and had to be manipulated then to get it working each time that happened ... meaning of course that it HAD to be replaced ... I never did put a meter on it to be sure the contacts were all making reliably even when it did mechanically function ... no matter now because I replaced it with a brand new 2 pole 50 amp motor rated switch I had laying around.
So where I'm at now is I have GUESSED at how things were supposed to be and I replaced all burnt up connectors and torques everything down. I am reluctant to try it out again before seeing a manual though ... don't want to ruing windings or burn out the diodes (I think that is what those components must be. One thing I guessed at in my repairs was that between two plates (some of these diodes are attached to these plates) there was a bolt that apparently was supposed to have been insulated from the botttom plate but mechanically solid at the top where there was under it's top nut these conductors I mentioned that had in one case apparently burnt free and with the others really really loose! Lot's of evidence of arcing. Reason I think that the bolt was supposed to have been insulated at the bottom plate was that there was a nylon bushing and two rubber washers but the bushing was so worn and deformed and everything was so loose and burnt looking that it is hard to say for sure what was supposed to be. I thought to er on the side of caution so I replaced the bolt and damaged insulator looking items with a heavy duty rubber isolator, a rod coupling and a piece of allthread creating a very solid yet inulated bridge between the plates ... they won't buzz and they won't flex to short against anything (which is what I am sort of assuming the original setup MIGHT have been designed in the same way?/?? Anyway that is where I'm at ... it's ready do test but I'm unsure it's right? I would even love to see generic connections of diodes in a welder ... are they set up as a full wave bridge rectifier?? If that is so I could check it out from that standpoint ... Help? Doug
Doug:
Can't help with the electrical questions, but a little history might help with the schematic. Century (also Solar) manufactured on it own for many years and also supplied welders to Craftsman (Sears) Coleman, and many others under their specific brand names. Then, Clore Automotive bought the company and continued to market welders for some years, before selling the welder business to Lincoln.
I discovered the above a few years ago, while trying to get a manual for a "PowerMate (Coleman) for a club tha owned it. I did succeed in downloading a surprisingly good manual from Clore, complete with schematics, for an equivalent Solar model, but have no idea where you might look now that Lincoln has taken over. The best bet might be owners of similar models in output and design, if you can find some. Hope this helps.
Doug,
Any of the schematics I've seen for simple welders is that the rectifier is a bridge. If so, you should be able to see 4 similar looking devices of fairly substantial size which would be the diodes.
You mention 2 plates. They could be the mounting/heatsinks for the diodes. Normally there would be 2 diodes on each plate and if the diodes are not totally insulated from the plate then the plates are insulated from each other and the welding box. On one plate the diodes would have their cathodes (negative) connected together and on the other the anodes (positive) would be connected together. The connection will be by jumper if insulated or via the plate if they bolt onto the insulated plate (this is the most likely). The high current DC connections would be made at these places. Note that you can usually get the same high current diode with either its anode or cathode connected to the mounting stud. The model number won't be identical but will have a letter after it probably an "R" for reversed.
Each of the 2 power leads from the transformer would go to the other end of one diode on each of the 2 plates.
If you haven't done so I would trace the wires and make a sketch of the circuit. If you can make some sense of it then, you could use an ohmmeter to check for shorts to ground or even bad diodes. Of course, you may have to do some disconnecting for accurate tests.
Good luck
You can get full wave output with a center tapped transformer and only two diodes. I don't know if this is done in welders but it is common in other power supplies (like battery chargers).
You can parallel diodes together to get increased capacity so you could find more than you expect.
Sears has parts and diagrams but you need a model number to make their search work (look for a plate somewhere). I've found parts for many things made by other manufacturers.
Lincoln has lots of manuals as pdfs, again you need some sort of model number to start you off.
The other box is probably the high frequency unit for TIG.
Have fun,
Bill
For a schematic, owners manual, or just about anything for Century brand welders and battery chargers call Lincoln Electric/WCTA at 866.236.0044, option 3. You'll need the model number, preferably the
full model beginning with 110-XXX. The tech guys are very good, they
worked at the original plant in Minneapolis before the company was sold
twice; first to Clore then to Lincoln. They will be glad to send or email
you the info you need.
If you don't feel confident after studying the schematic, DON'T plug it in.
The Tech Service guys can point you to a WCTA service center in your area. I'd advise you to call the shop first, some are more reasonable rate-wise than others for what you need (wiring verfication).
Of course, it also follows that some are more competent......
Good luck, should be a good welder for you.
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