Start amp problem maybe?

[Daniel DK]

Hello out there

We have a new problem with our cut quality. Even though we put a whole new set of electrodes etc, then aften the first cut/pierce the nozzle gets damaged. To me it looks like that the ignition is to strong and melts the nozzle. After looking at the plasma arc through a welding helmet I can see that as illustrated on one of the pictures the arc gets bend of course, because of the nozzle getting damaged after pierce. This a 1.5mm nozzle on a 3mm s235 steel plate, running at 85amps. We tired with a 2.1mm nozzle and it does not get damaged after the first pierce but you can clearly see the ignition marks on the nozzle side.

With our little knowlegde we think that I may be to much start amperage but we can not adjust it on the machine or unit...

Any ideas on what the problem could be? Because we have become blinded with thinking about it

Best regards
Daniel and Lauri from Denmark

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[weldguy]

I suspect you have water and or oil contamination in your air supply. With contaminated air even the 1st pierce will destroy a nozzle. I bet if you looked inside the nozzle you will see swirling black or gray stains which are deposits from whatever is being burned up. This will superheat the arc and cause instant damage to your consumables.

What are you using for air filtration?

Do you drain your compressor tank often?

[Daniel DK]

Hey Weldguy.

That I know a bit about from past experience so I have checked that, there is a little bit of black/brown ish marks on the inside of the nozzle and a bit on the electrode. But not so bad that I think that could make this much "damage" to the nozzle. I've seen much worse🫣
This is kinda sketchy but I am using a tower freeze to dry the air. Fresh filter intake on top and intake for the compressor on the bottom. After the compressor there is a normal 3 part filter system and then before it goes through the amplifier there is one more water filter.

When I think about it, I have not drained the compressor in a while I'll do it quickly and then when the other problem with the movement of the plasma head is fixed i'll test it again

[jimcolt]

Damage on the exit orifice of the nozzle is most often caused by piercing too close to the material. I see some splatter on the face of your nozzle that is the color of steel, not copper!. Because you are using a non shielded set of consumables.....this problem is most common. Shielded consumables (like Hypertherm torches use) use the shield to double insulate the nozzle....making orifice damage less likely. Water in your air causes shorter electrode wear in the form of an increased depth of the wear pit on the hafnium emitter in the electrode.....so I would definitely steer you toward increasing pierce height and maybe pierce delay time as well (if pierce delay is too short then the x-y axis motion begins before the pierce is complete, causing arc blowback on the nozzle). Depending on what brand and model torch you have.....there may be shielded consumables available (though I don't think so). Some users of these older technology non-shielded torches use aftermarket copies of older Hypertherm style shielded torch consumables that increase nozzle life and allow for minimal damage from close piercing and short pierce delay. Jim Colt

[Daniel DK]

Hey Jim.
Thanks for your reply. I have been using some calibrated shimes to double check the pierce height, but I have not been playing around with the pierce delay. I will try it first thing monday, i'll let you know how it goes!
Your reply was very inlightning, have been watching some your videos as well! Big fan!
Again thanks for you reply - Daniel