Air problem with Powermax 1250

[koper]

Hi,
I have a Powermax 1250 plasma cutter. I'm facing a problem that after a very short time (about 20-30 seconds) after firing up and start cutting, the machine stops and the orange led indicating air supply goes on. since my air compressor has a tank capacity of 150 liters and the air pressure switch is set to 9 bar, it seems to me that the problem is in the plasma cutter and from lack of air. would like to hear your comments and an advise how to correct the problem.

[Plasma-art]

Do you have a pressure gauge directly at the machine and is that indicating a constant good pressure without any major drop?

[adbuch]

I agree with Plasma-art on this one. I have an inline air pressure gauge installed directly at the gas port entrance to my Hypertherm Powermax 85 and have my pressure set so that the gauge always reads 100 psi while air is flowing thru the torch. If your low pressure light comes on, then it is telling you that you have insufficient air pressure to the cutter. Is this a new problem with a setup that was working properly before, or it this a new setup to you and you are just getting it up and running?

David

[koper]

Thanx for your replis. no, I dont have a pressure gauge on the plasma cutter bot it's a short distance from the compressor to the cutter. I'll follow your advice and I'll install a gauge on the cutter and update.

[adbuch]

Thanx for your replis. no, I dont have a pressure gauge on the plasma cutter bot it's a short distance from the compressor to the cutter. I'll follow your advice and I'll install a gauge on the cutter and update.

[koper]

As you can see on the attached picture - the air pressure gauge shows that the pressure is about 5.7bar, which I believe should be sufficient, but unfortunately the problem remains. I took a picture of the machine's front panel - the led in the rectangular icon, the one with the sign of air cylinder,
is blinking, in the picture it's not lit, because I didn't managed to catch it when it's on. I suspect that inside the machine there is some air pressure sensing device which might be faulty and gives indication that there is not enough air pressure. any idea/insight will be a blessing.
Unfortunately I wasn't able to upload the pictures. I'm getting a yellow triangle with an exclamation mark inside it. the files are one of 4.7mb and the other 1.8mb, so I don't know what the problem is (as you can tell - I'm not a computer geek).

[adbuch]

Does your air pressure gauge reading remain constant while the machine is cutting?


When you upload these large files, you can use a program like BitZipper to compress them and then upload. Another option is to open you image with IrfanView or similar and resize them to reduce the file size. This is what this file will look like when you unzip it.


David

New.zip

(1.38 MiB) Downloaded 44 times

[weldguy]

5.7 bar is about 82 psi which is barely enough, your right on the edge. You want to be able to see around 90-100 psi at the inlet of the plasma cutter while air is flowing when the machine is cutting to know for sure your air is not the issue. Could just be an air filter starting to plug up and restrict flow. Should be an easy fix.

[koper]

Could just be an air filter starting to plug up and restrict flow. Should be an easy fix.

Is there a filter inside the machine? I do have a filter at the inlet but the reading on the gauge installed after the filter shows almost exactly the reading on the gauge on the compressor, so it's not unreasonable to assume that the filter is intact.

[Plasma-art]

I do have a filter at the inlet but the reading on the gauge installed after the filter shows almost exactly the reading on the gauge on the compressor

Is that when the air is flowing/machine is cutting or just standby/idle pressure?

[SegoMan DeSigns]

When was the last time you pulled the air cleaner and cleaned it out? an upgrade cartridge is available I believe.

Go here / click on documents to download the manuals and save to your hard drive for future use.

https://www.hypertherm.com/en-US/search/?search=1250

2nd Link (repair Manual) Pg 70 (section 3-37) shows the internal cartridge removal.

[koper]

When was the last time you pulled the air cleaner and cleaned it out? an upgrade cartridge is available I believe.

Go here / click on documents to download the manuals and save to your hard drive for future use.

https://www.hypertherm.com/en-US/search/?search=1250

Thanx, I followed your advice but it seems to me that it's not applicable for the Powermax 1250, they are stating other models. the torch on the machine is a T80, btw.

[SegoMan DeSigns]

OK my 1250 came with one hanging off the back of the unit (I mounted a motorguard in front of it as well) , has yours been removed? How does your pressure regulator work?

[weldguy]

Could just be an air filter starting to plug up and restrict flow. Should be an easy fix.

Is there a filter inside the machine? I do have a filter at the inlet but the reading on the gauge installed after the filter shows almost exactly the reading on the gauge on the compressor, so it's not unreasonable to assume that the filter is intact.

Don’t think the 1250 has an integrated filter

Ok so your filter may be fine but your pressure is still too low.

Pressure switch is 9 bar you say so why 5.7 at the plasma?

[koper]

How does your pressure regulator work?

I'm not sure but I think that the problem may be with the internal pressure regulator of the machine. is there a way to check it more thoroughly than by turning the Amperage knob ccw? is there a way to connect a pressure gauge to the internal pressure regulator's output to monitor the actual pressure?
As per the cartridge adapter, as I mentioned before, it seems to me that it's not for the T80 torch, however, from the pic of the existing torch, it can be seen that there no such a device on it.

[adbuch]

Does that 85 psi gauge reading remain steady while air is flowing thru the torch?
David

[koper]

Does that 85 psi gauge reading remain steady while air is flowing thru the torch?
David

I can't tell because now the "Air" led is immediately on, not allowing me the 20 seconds of cutting, as it was before. however, when I turn the Amperage knob fully ccw and the air flows thru the torch - the reading on the gauge drops to 4bar/58psi.

[Plasma-art]

Thats the most likely cause of the issue.
There is a restriction between the compressor and the plasma cutter somewhere dropping the flow and thus pressure.

[adbuch]

I agree. If your pressure drops too low at the entrance to the cutter, then the air light will come on and the cutter won't cut. How large is your compressor, and what size air line are you running to your cutter from the compressor? I run 3/4" dia. copper pipe around the shop from the compressor, it is sized down to 1/2" out in the machine shop were the plasma table is located, and after it meets the refrigerated dryer it drops down to 3/8" ID hose to the plasma cutter. My gauge at the cutter maintains 100 psi while the air is flowing thru the torch as it is cutting.

David

[tnbndr]

I agree that your compressor is not providing enough air.
I also noticed that in your picture of the front panel your cut type switch is up for perforated metal which keeps the torch lit at all times. It should be in the middle position for normal plasma cutting.

[weldguy]

Man you are really over complicating things. Just turn your air pressure to the plasma cutter up, super simple.

[koper]

It should be in the middle position for normal plasma cutting.

Thanx, I'll try it.

Just turn your air pressure to the plasma cutter up, super simple.

Do you mean the built in regulator - the one that it's knob on the front of the machine?

[weldguy]

Do you mean the built in regulator - the one that it's knob on the front of the machine?

No, I mean the supply air coming into the back of the machine. 5.7 bar is barely enough. Crank that up to 7 bar and then use the regulator knob on the front of the machine to reduce that pressure to 5 bar when the air is flowing. That will more than likely fix your problem.