Your electrician friend is either pulling your leg or he's utterly clueless...
Spoke to him fleetingly over Xmas. He assures me that the power generators do not like 3 phase welders on the system for metering reasons.
Engine driven - fine - but fed from the mains is 'at least not encouraged'. He is a reliable and well-informed ex regional electricity board leccy (retired), so should know what he is talking about.
Regards, RAB
Well, I can be fooled about a lot of things... but I've done serious time repairing welding equipment for a living and have the T-shirt and Lincoln and Miller ball caps to prove it, so I don't fool quite so easy on that one....
From 1980 -1984 I worked for a large fabrication shop in the SF Bay Area (Northwestern Equipment & Supply Co.) that in addition to having a rather large steel fabrication shop, also rented, sold, and serviced industrial welding equipment and supplies. We had over 200 welding machines in our rental fleet, plus dozens more in the fabrication shop. But no 2-phase machines in the lot.
During those years I serviced, installed, repaired literally 100's of welding machines belonging to us or our customers. Almost exclusively 3-phase or gas/diesel driven machines from 200 to 2000+ amps output.
I've worked on equipment in a huge variety of Bay Area industrial businesses... every oil refinery in the bay area, Pacific Steel Casting , TASCO valves, Mothers cookies (RIP), OAK and SFO airports, lots of work at Moffet field including the big wind tunnel and that enormous "hanger 1".Â
I serviced machines at the old Airco Welding Institute in Oakland (they had about 60 3-phase machine in the fleet for their students).
I've fixed machines in countless smaller shops that few folks have heard of. But in ALL of them, the welding equipment was genuine 3-phase. Never ever seen a 2-phase machine or a 3-phase machine that only used 2-phases.
I spent 4 days at the Lincoln Electric Co. Factory in Ohio, to become a "factory certified technician". In 4 days of class discussion about welding equipment no one EVER mentioned any 2-phase equipment, or any metering problems with the millions of 3-phase welders in the world.
I walked away from Lincoln with about 50lbs of books and service manuals for all of the then current Lincoln welding equipment. Any 2-phase stuff in there? Nope.
(Later, I consulted with Bill Urbanski and the senior designers at Lincoln and proposed several changes to the control circuitry of the LN23-P wire feeder and one of the large Sub-Arc welders that was new at the time. My suggestions were incorporated into the newer versions of those machines and my SJD initials appear on schematics in the service manuals for those machines.)Â
From 1985-87 I worked for a smaller company in Hayward doing basically the same thing. Still never seen any 2-phase welders.
In the early 90's I did a lot of work for 2 large stainless fabrication shops that made wine fermenting tanks and equipment. I repaired dozens of genuine *3-phase* welders for those folks.
By '97 I'd pretty much moved away from the equipment repair scene, so my direct experience ends there.
I'm pretty sure that if 2-phase machines commonly existed (or 3-phase machines that only "use" 2 -phases) that I would have seen or at least heard about ONE of them in my lifetime...
Most 3 phase welders are just a simple 3-phase transformer that feeds a standard 6 diode 3-phase rectifier then regulates the current/voltage appropriately. There's absolutely nothing in there that's gonna "fool" anyones metering equipment.
Here's a schematic for a Miller DeltaWeld 650. 3-phase, 240/480 volt input. The genuine 3-phase input is clearly show at the left side...
http://www.weirdstuffwemake.com/sweetwatergems/geek/misc/deltaweld_650.gifPlease ask your friend to send me a schematic for any "2-phase" welding machine, or provide me with a make/model# of one so I can look it up for myself. Seeing is believing.