Plasma Cutter Troubleshooting

The Most Common Problem - The Plasma Cutter Is Too Small For The Metal Thickness

So, keeping this in mind, whatever maximum metal thickness you think you will cut. Buy a cutter that is one step up. At least a ½ inch or 50 amp plasma cutter (and a suitable air compressor). Anything less and you will probably be restricted to cutting sheet metal only.

You may also find the amount of consumables you save in a year with a bigger machine will pay for the larger unit.

Insufficient Or Excessive Air Pressure

Consult the owner’s manual if in doubt and make sure you maintain optimal air pressure for the amperage being used. Each cutter will be different so it’s good to double check the recommended air pressure settings.

   Air Pressure Is too High

If the pressure is too high this will dissolve the arc column and weaken the power of the plasma arc.

Things to check:

• Air compressor pressure

• The pressure between the Air filter and air compressor

• If the air filter relief valve is faulty or set too high

   Air Pressure Is Too Low

If this occurs then an optimal plasma arc cannot be formed. This will result in a poor quality cut and built up slag.

Things to check:

• Is the compressor providing enough air?

• Are the air channels blocked?

• Is the air filter relief valve set correctly?

Plasma Cutter Not Arcing

Solution:

Chances are there is a burned out component(s) inside. If the cutter is still under warranty. Call the manufactured (do not open it up as you will void the warranty).

If, however the unit is past warranty and you are handy with these things then once you open it up, discharge the power, and look for broken parts. Some of the most common ones are:

• Blown diode, 
• The leaking capacitor (oozing out the top), 
• Burned up resistor, 
• Broken relay, 
• Broken chip/ MOSFET (chunk missing from the chip).

Contact your local welding store for some advice and parts.

No Arc Between The Contacts

Solution:

Well, turn the machine off before messing with the metal parts.

Remove the cover.

Check your point gap. Your problem is likely that spark gap has to be widened to around .040" to increase the spark voltage at your torch.

The pad that contacts the electrode may move away from the electrode under air pressure. A spring on the pad shaft may overcome by the air pressure and pushes the pad away from the electrode. The spring may get too hot and fatigued causing the pad to not return to electrode contact after the switch is unkeyed. The pad needs to contact the electrode at key up when the air moves it away from the electrode a gap is created causing electrons to flow through the gap to allow the plasma to be produced and to flow. Replace the spring.

Make sure it is clean and set correctly. Hope this helps.

The Resistor Gets Very Hot

The plasma cutter isn’t working, and the resistor gets very hot.

Solution:

Remove the cover and inspect the inside the lower front part of the unit and hold the torch switch to see if you are getting a spark inside the unit there. If you don't see any spark inside the unit while holding the torch trigger, then something has failed on your lower board there.

Check out the resistor which is located behind the arc points and is standing upright. Remove the board unsolder and install the new one. Hope, it’ll work correctly.

Everlast PowerPlasma 80S Troubleshooting

I’m using an Everlast PowerPlasma 80S plasma cutter. I want to cut some 1/8-inch hot rolled steel.

How do I set up the plasma cutter?

How much amperage do I need for the metal thickness?

What air pressure do I need for the metal thickness?

Solution:

On the plasma cutter's front panel, you’ll see a pressure gauge. At first, it's set pretty low, right around 15 PSI.

Experiment with the settings like so:

• First, turn up the air pressure to about 60 or 65 PSI for 1/8-inch thick hot rolled steel.
• Push down the knob to make sure the pressure regulator is locked in place.
• Turn the amperage down to 20 amps at 60 PSI, give that a try.
• Then cut it at 25 amps and 30 amps and check the quality of the cut.
  • At 20 amps the cut will take a long time - it may just barely cut through the metal. 
  • At 25 amps the cut will go a little quicker, and the 25 amp cut will have a few smaller kerfs. 
  • At 30 amps the cut will look about the same width as the 25 amp, but it’ll cut much more quickly and easily!

Remember!

It's the air pressure (not amperage) that makes the difference for a clean and good cut. As long as you have the adequate amps to cut through the metal and move at an optimal speed, experimenting with the air pressure is the best way to get the most accurate cut.

Is A Drag Cup Necessary?

Is a drag cup (shield) necessary when running 30 amps or less plasma cutter?

Solution:

You need a drag tip if you are going to drag. As a general rule, if you are cutting at over 40 amps it is good practice to use a drag shield to help extend the life of your tips.

AHP AlphaCUT 60 Troubleshooting

I was using AHP AlphaCUT 60 plasma cutter. The nozzle was screwed on the end of the gun and holds everything together. I was getting right down on the metal and touch the metal while I was cutting, the machine short out. The nozzles and tips worn out - they're right down in the flame getting hit by spattering and get all burned up and crispy.

How can nozzles make plasma cutting easier? Can I use speciality nozzles to improve plasma cutting?

Solution:

Any standard tip works fine if you’re free-handing and working in tight spaces. However, if you move or shake a little or like to make an extended cut, it’s better to replace regular nozzle or cap that features a drag guide on it. It screws right into place, allows you keep your distance and you’ll be able to see what you’re doing.

You can also use a drag cup. Its brass part is insulated from the tip. So, it remains cool. It comes with relief cuts so that spark can escape. It’ll let you go right down on your metal. Furthermore, it directs more of the light and sparks downward rather than above.

Hypertherm plasma cutters all feature drag tips. The Newest cutter has built-in compressors and automatically set your air pressures for you.

Irregularities in the cut surface

I see irregularities in the cut surface and these appear only in one axis. What can be the possible reason?

Solution:

The reasons may include too high gas flow or damaged consumables.

Check the gas flow and replace the consumable if you found any.