On the new version 255EXT, the one pictured (has a gas purge button, spot timer and 4 fan cooling) when facing the machine, the positive electrode connection is on the right and the negative electrode is on the left. On the previous model 255EXT, these were switched. The reason they were changed was to accommodate the additional internal electronics installed during the upgrade. So, most likely, if you have a new manual, they just forgot to replace or change one of the pictures when they updated the manual. The information is correct as indicated, you just have to install the leads according to the manual on the correct side as marked on the welder.
How do I know?
There I was ... I was lucky enough to call Everlast at the right time and got one of the first new version 255EXTs before it had even been advertised. At the time, I had never touched the TIG welded before. I had printed the manual off of the website but the new version was not even on the website and the manual was for the previous version. I RTFM several times over the next few days, and watched a lot of Jody's videos, crash course in TIG welding. When the welder came in, I hooked it up, just plugged in the leads on the side I memorized not even looking at the welder itself. The welder (or maybe weldor) welded like crap, blew up the tungsten. I checked gas and tried a little messing with the controls but was afraid that there was damage in shipping and didn't want to damage anything more so I shut it down and sent Everlast a note.
That was Saturday evening, early Sunday morning I got a call from someone at Everlast, don't remember who it was but I think someone involved in the design. He had me go out to the garage and look at the welder and tell him which side the leads were hooked up on. Just about that point, having done some studying on this, I saw the positive indicator on the welder and the torch lead attached to it, bingo, lights on, feeling really stupid at that point. Anyways, the guy at Everlast was very nice, we shared a few laughs and he told me suspected the cause because they had changed the leads with the new welder. I changed the leads to hook up correctly and the welder has performed flawlessly every since (though not necessarily the weldor). Anyways that is why I suspect that the manual has the leads on different sides on the drawings.
Couple things though. I was impressed with Everlast customer service calling on a Sunday morning to ask about the issue. I thought that was best in class. I was also impressed that who I talked with was quite patient and affable with my ignorance, as he had gotten up on a Sunday morning to call. Finally, I have learned to weld on the 255EXT, hours on hours of practice and modern art for the recycle, made about every welding mistake a person can make in learning and the welder just keeps on working. For me it has been an excellent machine that I continue to use regularly.
Jim S.
Miller 211 Autoset
Everlast 255EXT
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Hypertherm 30Air
Everlast 350EXT