EXT versus EX

[srp]

I probably brag more about the 250EX than most, Our first 250Ex was bought used and had been tuned up by a local shop to weld at specs, It had different resistance pots on the pulser and ac balance. It will pulse at .1pps and adjust all the way down to no cleaning action if needed, With red tungsten I can weld at 250 amps on AC and keep a sharp tungsten ( super sharp), no dingle berries and no tungsten splitting. I can go for days without sharpening the tungsten on AC.

When I got the new 250EX, it would only pulse at 1pps and would only adjust to about 60% electrode negative with about 1/4 inch cleaning action minimum, and would not hold a sharp point. After talking to Oleg, he authorized these mods for the new 250EX and now it welds as good as the first. Hopefully these mods will added to the newer models.

After having a super stable arc cone way down on the tip of the tungsten, it would be hard to go back to a machine that has a dancing arc.

[srp]

After reading some of Todd's posts, the 250EXT pulse has been bumped to 500pps on AC, If the AC frequency is bumped up to 250 hertz or higher, I would consider getting one. The 315EXT only being offered in three phase is a waste, 90% of Everlast customers are hobbyist and do not have three phase at home. I would chose the 315EXT over the 250EXT if it was single phase.

[Rambozo]

... adjust all the way down to no cleaning action if needed, ...

So it would go to DC?

[srp]

So it would go to DC?

No, but it will adjust down to no etched or visible cleaning action. Even turned all the way down, it has plenty enough cleaning action to leave beautiful welds on aluminum. The arc is very focused and stable, allowing very tiny welds on AC.

[Rambozo]

No, but it will adjust down to no etched or visible cleaning action. Even turned all the way down, it has plenty enough cleaning action to leave beautiful welds on aluminum. The arc is very focused and stable, allowing very tiny welds on AC.

Do you know exactly what was done? It sounds like some great mods.

[srp]

Do you know exactly what was done? It sounds like some great mods.

Yea, the pulser frequency and AC balance potentiometers have both been replaced by 1 meg pots. Actually they ohm out at 1100K. The older 250EX has been modified for 2.5 years and the new one for about 7 months with absolutely no problems. Oleg is well aware of these mods, I'm sure he tested them as well.

My Syncrowave 250 will pulse at .25pps or one pulse every 4 seconds. Getting the 250EX to pulse at .1 was important to me, I slow pulse when welding chrome-moly tubing at about .3pps. Anybody that has welded chrome-moly knows how important it is to keep heat saturation down, so it does not crack at the welds edge.

[Rambozo]

Interesting. I will keep that in mind.
I have a Cyber-TIG that does really slow pulsing, too. In fact you can set the duration of both the low pulse and high pulse independently. But to be honest, for slow pulsing I usually use the pedal. I wish there was a pulser where you could set a ramp in and out like you can with the pedal instead of a sharp transition. Then I would probably use it more.

[geezer]

The 250EX is limited to 250 amps output.

The 250EXT allows one to set +30% EN bias, which could give a nice output power boost in AC welding mode. For example, if you set the EP output to 250 amps, the AC bias to +30% (which could give 325 amps EN), and the A/C Balance to a setting that would give 33% EP, that would give an overall output of 300 amps average with that mode. The 250EXT should be able to theoretically at least, melt some pretty thick aluminum.

That is interesting thinking on your part,,,it may help explain why Todd is blowing 60 amp breakers when he up's the hertz at high amps,,a combination of AC Bias and hertz could be beyond the machines limits..there are no free lunches in life,,,more power out means more power in,,