Submerged Arc Welding question.

admin

We are going to procure a Submerged Arc Welding M/c, as per following requirements-Application- For fabrication of Cylinder Block of Diesel Locomotives.Power source: 240-1200 Amps.Power supply- 415 V AC, 3 Phase, 50 HzWire dia- 4.7mmWhat should be the Voltage range for the power source? What should be Open circuit Voltage?How do we arrive at these values?
Reply:That wire diameter is close to 3/16 inch.  That is way beyond me.  Is that some kind of robot wire feed?
Reply:The Lincoln procedure handbook would be a good reference.  3/16 inch is very big wire.  In some cases people are running 5/32 at over 900 amps so 3/16 could run regularly around 800 to 1000.  for example :  3/8 plate, with a 5/16 fillet run at 725 amps and 34 volts traveling at 27 inches per minute.Or:  one inch plate with a 3/4 fillet. 975 amps and 40 volts traveling at 7.5 inches per minute.   Unless your plate thickness is over half inch I would not even entertain using such large welding wire.  Of course the fixturing of your gun flux feed and positioning will be more technical work than setting up a sub arc machine.  That is the easy part.
Reply:I am particularly concerned about the operating Voltage and OCV. Other parameters (like wire size etc.) have already been fixed by our design department, and I have little control. Please have a relook at my specific questions:What should be the Voltage range for the power source? What should be Open circuit Voltage?How do we arrive at these values?
Reply:>I'm thinking that lotech was trying to refer you to some good information contained in Lincoln Electrics "The Procedure Handbook of Arc Welding". Try pages 6.3-28 through 6.3-73 for numerous examples of electrode sizes, current ranges and load voltages for various joint configurations. Of course the exact load voltages and OCV are better provided by the manufacturer of the actual machine to be put into service.
Reply:The open circuit voltage will be in the 30 to 40 volt range if you are using constant voltage.  If you are using constant current then normally the transformers run around 75 to 80 volts open circuit.  I am not sure why these figures are a concern to you unless you intend to design your own welding power supply.
Reply:Out of my depth here, but don't machines of this size and price range come with a knowledgable distributor or company rep that can set you up and answer any questions? I would think you should be able to pick up the phone and have a guy show up at your facility ready to set up the machine and explain how to work it. My job has bought equiptment for on road use and we have had field meetings with reps just by calling them. Just my 2 coppers, good luck in any event!If you don't have the time to do it right, then you definitely don't have the time to do it over.
Reply:Originally Posted by Sandy>I'm thinking that lotech was trying to refer you to some good information contained in Lincoln Electrics "The Procedure Handbook of Arc Welding". Try pages 6.3-28 through 6.3-73 for numerous examples of electrode sizes, current ranges and load voltages for various joint configurations. Of course the exact load voltages and OCV are better provided by the manufacturer of the actual machine to be put into service.
Reply:Originally Posted by kbhatiaYa, perhaps I am a dummy and I don't have this handbook. But my expectations about such forums are that they give you readymade answers!
Reply:Everyone always wants the easy answer.  Try picking up a book and reading it. Don't come on here EXPECTING an answer.As Lotech stated, one person doesn't know everything, it's impossible to know all aspects of every type of job or skill.  Perhaps you should raise your own expectations?John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:For some who have never seen sub arc in production.  I am clipping this pic I took years ago.  This particular past employer would not like a complete pic on the web.  You can see two welding heads.  One operator with gonads could run up to just short of 900 amps on both heads.  One parameter slightly off and it would be blow through time .... that is blowing through almost 3/4 inch of material! Attached Images