HYPERTHERM PLASMA CUTTER FLAME-OUT

[enzed]

It has happened twice recently that the torch moves to a new pierce position but fires with a soft 'pop' sound and nothing further happens - no flame, and the process comes to a standstill. This is with a Pwermax45 machine torch. Excessive moisture in the air supply perhaps? I will appreciate it if anyone can tell me what is the cause of this and how it can be corrected. Enzed

[adbuch]

Perhaps insufficient air pressure. Best to have an inline gauge mounted right at the air inlet to the cutter. I set mine to 100 psi with air flowing thru the torch. This is for my 45xp and 85.
David

[acourtjester]

You did not say which nozzle you had on the torch, sometimes the fine cut will miss fire, this is true is the nozzle is new. The reason for the process stopping is there is no arc Ok signal due to no plasma stream, so that part is normal.

[adbuch]

You did not say which nozzle you had on the torch, sometimes the fine cut will miss fire, this is true is the nozzle is new. The reason for the process stopping is there is no arc Ok signal due to no plasma stream, so that part is normal.

For new Finecuts it is a good idea to increase the cut height from 0.060" to around 0.075" to 0.080" for the first several hundred pierces. Then go back to the book setting of 0.060" for cut height.
David

[enzed]

Thank you to all who responded.
I did have enough air pressure, and do have a pressure gauge in the system very close to the Powermax45. Yes, the 'flame-out' happened with a new nozzle and electrode, both standard for the 45m machine torch.

[weldguy]

To determine if dirty and or wet air is an issue inspect an electride and nozzle with some use on it and is you see excessive black or grey swirling deposits inside the nozzle and around the electrode your air should be cleaned up. This may not be your issue but can lead to a lot of problems.

[WyoGreen]

Hypertherm uses a blowback arc start system, where the nozzle is shorted at rest, then "blown back" by the starting air pressure to strike the arc. I wonder if the nozzle is sticking sometimes causing your problem. You might try either cleaning your consumables, or perhaps putting new ones in to see if that cures your problem.
Steve

[enzed]

Thank you Weldguy and Wyogreen, also very usefull advice.

Yes, there is some grey swirling deposits inside the nozzle and on the electrode, but I would not describe it as "excessive". In future, I will clean the consumables more frequently and as best as I can. Interestingly, the flame-out does not happen with new consumables. At the same time however, I keep a close watch on their condition, and especially on the electrode, and do not wait until the crater formed in it is so deep that the cut becomes a terrible gouging, instead of cutting through.

[weldguy]

Thank you Weldguy and Wyogreen, also very usefull advice.

Yes, there is some grey swirling deposits inside the nozzle and on the electrode, but I would not describe it as "excessive". In future, I will clean the consumables more frequently and as best as I can. Interestingly, the flame-out does not happen with new consumables. At the same time however, I keep a close watch on their condition, and especially on the electrode, and do not wait until the crater formed in it is so deep that the cut becomes a terrible gouging, instead of cutting through.

Cleaning them won't do much if anything at all. The problem isn't so much the deposits that are currently on the nozzle and electrode, it's the fact that your air is contaminated and when this contamination passes through the plasma arc it gets burned up. The marks are just an indicator of this contamination issue. This can distort the arc, overheat the consumables, etc and this is what damages the orifice in the nozzle so the arc can no longer be constrained as it was designed to be. This leads to beveled edges on your cuts, poor pierce capability, etc but likely won't contribute much to your flame out issue unless the orifice is burned out much larger than it should be.

[enzed]

Thank you for your detailed explanation weldguy, and my apologies for taking so long to respond.

[adbuch]

Thank you Weldguy and Wyogreen, also very usefull advice.

Yes, there is some grey swirling deposits inside the nozzle and on the electrode, but I would not describe it as "excessive". In future, I will clean the consumables more frequently and as best as I can. Interestingly, the flame-out does not happen with new consumables. At the same time however, I keep a close watch on their condition, and especially on the electrode, and do not wait until the crater formed in it is so deep that the cut becomes a terrible gouging, instead of cutting through.

"Generally, standard all-copper electrodes should be replaced when the hafnium pit depth reaches 0.040 of an inch. Silver / hafnium interface electrodes can safely reach a pit depth of 0.080 of an inch."

https://www.hypertherm.com/en-US/resour ... electrode/

[enzed]

Thanks for that adbuch. I replace electrodes when the pit depth reaches 1.6 mm (0.06 inch), and if I remember correctly, this is based on the advice of Hypertherm. Perhaps I could push it to 0.080 inch.

[adbuch]

Thanks for that adbuch. I replace electrodes when the pit depth reaches 1.6 mm (0.06 inch), and if I remember correctly, this is based on the advice of Hypertherm. Perhaps I could push it to 0.080 inch.

This depends on which electrodes you are using. As Hypertherm states:

"As a reminder, the 0.040 recommended pit depth is for our standard all-copper electrodes. If you are using a silver electrode you can actually go to 0.080 of an inch, which is twice the pit depth of a standard electrode."

So if you are using the standard copper colored electrodes - which are the ones I use - then 0.040" wear limit. If you happen to be using the silver electrodes, then you can go to 0.080" pit depth before replacement.

David

[enzed]

Thanks adbuch. I was unaware that two types of electrodes exist. The ones which I use are copper and have a hafnium centre, so is then the 'silver' or copper version? I am a bit confused.

[adbuch]

Thanks adbuch. I was unaware that two types of electrodes exist. The ones which I use are copper and have a hafnium centre, so is then the 'silver' or copper version? I am a bit confused.

I don't know if the silver versions are even available for the Duramax torch. I use the regular copper electrodes, but there is one called the "Copper Plus" that is supposed to last twice as long as the regular copper version.

David

https://www.hypertherm.com/en-US/hypert ... opperplus/

[adbuch]

Henry - there is no consumable on the Hypertherm powermax called the "tip". The consumables are the shield, retaining cap, nozzle, electrode, and swirl ring.

David