I have a miller thunderbolt 225v AC arc welder

Try here

https://www.millerwelds.com/support/manuals-and-parts

I am pretty sure there is such a machine as you say.
So?

Changes between AC and DC voltage at the electrodes.



Q: What Type Of Stick Welder Works Best For All-Around Use?

A: A welder with an AC/DC output, whether its an electric arc machine like Miller\'s Thunderbolt or a gas engine drive like Miller\'s Bobcat.

DC welding offers advantages over AC for most Stick applications, including: easier starts; fewer arc outages and sticking; less spatter/better looking welds; easier vertical up and overhead welding; easier to learn "how to weld" and a smoother arc. DC reverse polarity (electrode positive) provides about 10 percent more penetration at a given amperage than AC, while DC straight polarity (electrode negative) welds thinner metals better.

Q: Does An AC Output Have Any Advantages?

A: Yes, if you need to weld on material that\'s become magnetized from friction, such as when hay, feed or water constantly rub against a steel part. A DC output won\'t work because of "arc blow," where the magnetic field blows the molten filler metal out of the weld puddle. Because an AC output alternates between polarities, it enables you to weld magnetized parts.

cc 230 isnt a bad welder. If it will be used for industrial purposes than i would go with a 440.

try you local welding/metal fabrication store. not sure where your located but pretty sure Oxarc will have what you need

The one labeled "work" is for the 'ground' clamp - to the metal.

"high" will give you the higher amerages on the dial, while "low" will give you the lower amperages.

Here is the location to find your manuals. Your serial # did not show a manual, search by Model name... http://www.millerwelds.com/service/ownersmanuals.php?model

i have a old miller thunderbolt CC*AC/DC welder its wire single phase 480 can it be switched to 220 single phase

The following link will provide you with information about a 225 thunderbolt. We have serviced many Miller welders over the years and find them to be very reliable. Good luck with your project.
http://www.millerwelds.com/om/o316g_mil.pdf

does this unit have a high side and a low side if it does plug it into the low side and try it.