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Hypertherm plasma cutter making weird air sound from inside unit

I have a hypertherm powermax 380 plasma cutter and when I turn it on it makes a weird blowing air sound from inside the unit. It sounds like air is leaking from someplace inside the machine. The unit fires ok and would work ok, but the air bleeding, (this is what I think it is doing), prevents the air compressor from being able to keep up with the air loss. It has not done made this sound before, or had this air loss problem before. I just got it back from getting worked on for a different weird air sound it had been making which I think was due to the psi being cranked too high on the compressor, because the guys at the shop couldn't find anything wrong with it and said it was working just fine. But, when I went to use it, this weird air leak sound. Any ideas?

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Open the cover (only after a day of not being plugged in).
Check the airline that comes in through the back of the case.
The air line has either fallen off or has a hole in it.

If you are a technician and don't mind working with thousands of volts of electricity that is inside the case, then and only then can you plug it in. Safety First. Rember the voltages inside this unit are lethal. It will not give you a second chance.

If you feel you are qualified, then plug it in and start it up, use it as normal, while at first watching from a 2 meter distance, you may immediately see and/or hear where the noise is comming from.

DO NOT under any circumstances put your hand or hands inside the box while it is live.

Try running a WOODEN stick (at least a foot long) along the length of the airline inside the case and around the valve as it enters the case. The sound should change in pitch when you find it.

If you think you have found it, DO NOT touch anything inside, until you have both DSCONNECTED THE UNIT from the power source and WAIT ONE DAY before putting hands inside the unit. Any storred or residual energy will have discharged by this time, making it safe to work on. Safety first. The voltages inside are lethal. This aplies to all Plasma Cutters. Good luck.

Posted on May 15, 2009

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I just had this problem with mine yesterday. I found the air was coming out of the tiny hose at the bottom of the air filter which is situated right at the back of the case where the airline enters the unit. It you lift the unit up and stick your fingers below, you can feel the air coming out. I took my airfilter off and put it back together and it stopped making the sound, so I'm not really sure what was wrong. I'm still looking for the root cause. I thought it might have been too high of an inlet pressure, but I doubt it since my compressor will only output 125 psi max and the filter has 160 psi max stamped right on it. But I suppose it could be an internal regulator set at 120 psi. But I've never had the air leak previously and it's always been used with my only compressor.

Posted on Oct 05, 2010

  • mkanwischer Oct 05, 2010

    I just called Hypertherm support 1-800-643-9878 to ask them about this, and they said that the air filter has an autodrain function if it gets a little water in it, that it will automatically drain. However, if it continues to leak there's a little rubber disk inside the air filter that needs to seat properly. When I dismantled my air filter and reinstalled it I must have fixed the poorly seating disk.


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My machine ht 2000 hypertherm very difficult to start but if on not long time it was shut down

Posted on Jan 30, 2010

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