Compressor to plasma CFM question

[RAW]

I need some help here.

If I have a 60 gallon compressor that is delivering 10.2CFM at 90psi and a plasmacutter that claims 6.7CFM at 90psi (though I tend to run it at 70-75psi), why is it that my compressor runs so frequently and for so long during a longer cut?

For example, I ran a file that CUT for roughly 10 minutes with just a few breaks between cuts. The compressor was full when I started, but it kicked on about 2 minutes into the cut and kept running for the rest of the cutting.

I would think from the specifications of the compressor and the plasma cutter that I would have enough CFM for my purposes, but . . . the compressor runs A LOT. And the problem with that is that it heats up my air supply, making it harder for my refrigerated air-dryer to do its job, potentially leaving moisture in the air supply (though I also have a dessicant dryer and a couple of other filters down-line from the dryer).

When the system is turned off, I'm not experiencing any air loss in the lines or filters.

Any suggestions? explanations? thoughts?

Thanks.

[mlaws1172]

Have you checked te intake filter on the compresser. And if it is a small filter change it out to a bigger one, it can make a big difference.
mike

[DSL PWR]

I think the plasma cutters are rated for manual use, which if memory serves me right is calculated to %50 duty cycle. So at your lower presure you are probably using about 10cfm @%100 duty, which is at the outside of what your comp. is good for.

[RAW]

Originally Posted by DSL PWR I think the plasma cutters are rated for manual use, which if memory serves me right is calculated to %50 dutie cycle. So at your lower presure you are probably using about 10cfm @%100 duty, which is at the outside of what your comp. is good for.

I was afraid of something like that.

Well, I've got a guy from a local air equipment place coming out to my shop later this week. I'll see what he has to say about it (though I'm sure he'll want to sell me as much as possible! )