MM350P: underrated or inaccurate

admin

My 350P works great. I have it switched to tell me the volts and amps (not WFS) while welding and it will show the amps for 4-5 sec after I shop welding.I was just wondering if this machine is underrated because I was welding some 3/8" with 035 solid wire in spray (not pulse) and it was reading some where aboout 320-350 amps. I though that alot of amps for 035 wire so just for kicks I switched to 045 wire. I turned it up to 32 V and 450 IPM just for kicks. I looked up at the machine and it said 36.2 volts and 458 amps. (it would hang around 36 volts and 445+ amps). Also when I am welding in short circ. like 18.5 and 300+- IPM with 035, I noticed the volts will jump up to 19-19.5. Is this normal.Can this machine really put out that much or is it just wrong?
Reply:I NEVER used the 350 P, but I would say its probably right.  One ipm of .045 wire = 1 AMP.I would not do that for long, the duty cycle has to be pretty low.I have a lincoln V350, it claims 425 amps @ 60% duty cycle.  I think it would do it, but I have not reached that point yet.  I DID run some dualshield @ 400 amps most of one afternoon on some bucket teeth.  With my machine, If I set the volts It doesn't always weld where I set it because wire speed, inductance, position, welding speed, and my personal style of welding.  If it reads one volt more, if I set it for one volt more, it welds better.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:so when I am welding at a preset number (say 19 volts) and the machine keeps bumping it up (to maybe 20 volts), then it is best to go ahead and turn the machine up to 20 volts?The machine says max amps is 400, so then how can I be welding and it say 458 amps.
Reply:If you set the volts to 19, and wire speed to 200 (.035) the wire will not draw enough current (amps) to make the welder work, so the voltage will be higher (the arc will be crap).  If you set the wire speed too high 450 for .045 and 19 volts, it MAY draw the volts lower than it was originally set.  I just set wire speed for the amps I need and volts for a good arc.Yeah, you could get 458 amps for a short time.  I have seen 400 amp spikes out of my ranger 250 while gouging.  Volts were probably chit, but....DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Both Miller and Lincolns (as well as the other major brands) machines put out more than they are rated for. I have done a lot of research on their ratings, duty cycles, etc. The MM350P is in fact rated at 350 amps 32 volts at 40% duty cycle. That is why it is imperative that you read your owners manual. It will answer a lot of those questions for you and could save you some very expensive repairs. Overloading is not covered under the warranty. My GX271 will peg 400 amps on a load test, but it is only rated 300 amps at 60% duty cycle. I have never turned my xmt304 all the way up just to see what it will do. The old Lincoln SA200's are rated at 200 amps at 60% duty cycle (probably the most under rated welder ever built) but for the most part would pull 350 to 400 amps on a load test. It's not the max amount of amps you can get, but how many you can get and use without toasting the machine.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:so is pulling more amps bad for the machine as long as you dont exceed the duty cycle?