question on AC/DC welder

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Ive been reading a lot about the differences between AC and DC welding but i had a question i couldnt find the answer to. I just got an AC/DC welder and was wondering what i plug the electrode and ground into to choose to weld under AC, DC+ or DC-Im guessing:Electrode into AC Electrode, Ground into AC ground = ACElectrode into DC Positive, Ground into DC negative = DC-Electrode into DC Negative, Ground into DC Positive = DC-I was wondering if my assumptions were correct. Thanks
Reply:Correct for the most part. The second in your list should have ended DC+, which should serve you for just about everything you need to do.
Reply:just wondering what size breaker are you running on - just curious - thanksThe main thing is not to panic or get excited Bobcat 250, X-Treme 12VS,  MM211Meltabo, Milwaukee,Porter Cable,Dewalt,MakitaVictor O/A, Ingersoll-RandEvolution Rage2, 40 amp PlasmaLincoln 225 AC/DC
Reply:whoops that was a typo. so it should be this:Electrode into AC Electrode, Ground into AC ground = ACElectrode into DC Positive, Ground into DC negative = DC+Electrode into DC Negative, Ground into DC Positive = DC-its hooked up to a 230v 60amp breaker
Reply:Originally Posted by c_johnsenwhoops that was a typo. so it should be this:Electrode into AC Electrode, Ground into AC ground = ACElectrode into DC Positive, Ground into DC negative = DC+Electrode into DC Negative, Ground into DC Positive = DC-its hooked up to a 230v 60amp breaker
Reply:ya i thought thats what it was but i wasnt 100% sure that reverse polarity was DC+just wanted to make sure i had everything correct\
Reply:Reverse polarity is DCEP (electrode Positive work Negative)Straight polarity is DCEN (electrode Negative work Positive)Think:  Straight polarity is like a minus sign for your electodeElectrons flow from Negative to Positve. Thats why plasma cutters use Reverse polarity to bombard and cut  the workOH NO, SOME HOW i MUST BE WRONG, SOMEBODY STRAIGHTEN THIS OUT.oH , never mind;    plasma cutters use Straight polarityLast edited by Insaneride; 12-29-2012 at 08:48 PM.Reason: plasma cutters use Negative voltage
Reply:Yep, a nice welder. I have a Dayton (Century) just like it. Not good with 6010 but runs all other rods I've tried just fine.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:ran though my first couple rods of 7018 today. im slowly getting the hang of it. thanks for all the help
Reply:I can't figure out why, on your welder, there isn't a separate amps scale for DC vs. AC.
Reply:Because it doesn't need one. It has the full current range on DC as well as AC. The internal components are better than those in newer buzz-boxes, but if they made that machine now, it would cost at least $800, and no one would buy it.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Originally Posted by Silicon-basedBecause it doesn't need one. It has the full current range on DC as well as AC. The internal components are better than those in newer buzz-boxes, but if they made that machine now, it would cost at least $800, and no one would buy it.
Reply:On the welder I have, there is a small extra secondary winding, just a few turns. It is on the primary (non-shunted) side of the transformer. I believe it is there to compensate for the voltage drop of the diodes and choke.Without that extra winding, the DC output would be 10 or 20% less than the AC output. However, the more common AC/DC welders where the DC output is barely half of the AC output, must be the result of a "shortcut" somewhere in the design.I have not seen the insides of those machines so I don't know what they are doing or not doing.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Originally Posted by Silicon-basedI have not seen the insides of those machines so I don't know what they are doing or not doing.
Reply:I haven't really looked into this, but I suspect that the main reason for such a drop in DC output vs AC output in the earlier AC/DC welders was the high cost and low availability of the high current diodes. There would be a small drop due to the voltage drop across the diodes, but that does'nt account for nearly all of the loss. Even now there is a substantial cost difference in the cost of the higher current diodes. Since it has been accepted traditionally and to be able to make the machines cheaper is probably why they continue to be designed that way.
Reply:Originally Posted by davido30093I haven't really looked into this, but I suspect that the main reason for such a drop in DC output vs AC output in the earlier AC/DC welders was the high cost and low availability of the high current diodes. There would be a small drop due to the voltage drop across the diodes, but that does'nt account for nearly all of the loss. Even now there is a substantial cost difference in the cost of the higher current diodes. Since it has been accepted traditionally and to be able to make the machines cheaper is probably why they continue to be designed that way.
Reply:No. I don't think you will see any difference in the actual performance of the welder; however, the higher rated diodes may prove to be a little more reliable in the long run.In order to change the actual output you would need to change other components in the design as well as the diodes. It is just that the diodes, excepting the transformer itself, are the most expensive components. Different welders have different designs. i.e. Some have voltage "taps" on the transformer to change the output. Some use a shunt that moves in and out which changes the coupling between the primary and secondary of the transformer to change the output. Still others use a "saturating" transformer to regulate the output.  Changing the diodes would not effect these controls.Component costs at the time of manufacture always effects design.
Reply:Just do some research, there's all kinds of information out there on this topic.-RuarkLincoln 3200HDHobart Stickmate LX235TWECO Fabricator 211i
Reply:Originally Posted by RuarkJust do some research, there's all kinds of information out there on this topic.
Reply:As stated, there is a wealth of information available. If you are really interested in getting started with some basic knowledge, this is not a bad place to start:http://www.esabna.com/EUWeb/AWTC/Lesson1_27.htmLike everything else, you have to start at the beginning and work up.Retired EE/electronics instructor.