3 Phase Arc Welder

By billvanderhoof (****)

Date 01-21-2005 06:10

Much smoother- the other two phases come in between the single phase peaks and nicely fill in that valley.
Bill

By ken4601 Date 01-21-2005 06:15

Sounds good. Reason I ask is because I'd like to get a HF box to do some aluminium welding. I know that in using single phase ac to TIG weld the arc will break when the voltage reaches zero in the + to - cycle hence the need for the HF box, but with 3 phase will it still happen?

By 357max

Date 01-21-2005 15:05

What is the model/brand of machine that you have? If it is a three phase transformer rectifier, You will only have a three phase DC weld output. You will not be able to get AC even if you disconnect the rectifier inside the welding machine. Three phase AC welding output will not work at all. If it is an inverter than it may work on both single or three phase. It may also produce both AC and DC welding output. Check your machine's owners manual, don't guess on this one.

By ken4601 Date 01-21-2005 20:21

Thanks for the comments it's a great site. Theres's a real commraderie in sites like these. Its a WIA Weldarc 230. Its a 20 year old basic transformer type of welder, no electronics in this baby, not even a rectifier. Its got a T handle that you twist and then you move the handle in an arc in the front panel to move the sliding core in and out to change the amperage.

By 357max

Date 01-21-2005 21:42

You have a single phase transformer welder. The 415 volt three phase input power will require dropping one hot line to provide 415 single phase. You will have two hot lines to the transformer and an earth ground going to the machine's chassis. You may find the purchase of a bolt on HF unit quite expensive. The negatives will be: no remote fine current/amperage control, no contactor (the electrode will always be hot), a contactor and control device for the contactor activation may be purchased at an additional cost. The biggest negative is arc rectification which turns into heat in the machines transformer. To protect your machine from arc rectification's heat you would be unable to weld at more than 70-90 amps with a 20% duty cycle (my guess from similar machines). At 1 ampere for every 1 thousands thickness that is about 70-90 thousands. 1/16 thickness or so and without the remote amperage control to prevent melting through at the start it is tough. Check out the price of a square wave ac weld output machine versus the cost of the HF with contactor control. Very kindly I would say don't do it.