If you look at the available consumables for a Hypertherm Powermax85 (85 amps maximum) you will see there are 45 amp Finecuts, 45 amp shielded, 65 amp shielded and 85 amp shielded consumables.
Each consumable set is designed to provide its best energy density (amps per square inch of arc area) at its rated amperage. For best quality cuts you choose the minimum amperage set of consumables that the cut charts (in the operators manual for the Powermax85) suggest for your material thickness. Then you set everything (amperage, arc voltage, cut height, pierce height, pierce delay, cut speed) exactly as the cut charts suggest for your material thickness and you can expect a good quality cut. Different sheets of steel have different chemistry.....so on occasion you need to adjust cut speed, faster to eliminate dross (resolidified metal that sticks to the bottom of the workpiece) , slower to produce a squarer edge. speed is the most common adjustment to improve cut quality...though advanced machine operators often will experiment with amperage and cut height (arc voltage) to fine tune for their particular cutting application.
So....running a 45 amp rated nozzle at 45 amps usually provides the best performance in terms of cut quality and nozzle life. If you increase the amperage past 45 (with a 45 amp nozzle), expect very rapid nozzle wear/failure. If you reduce the amperage below 45 amps with a 45 amp nozzle...expect cut edge angularity, slower cut speeds and a higher probability of dross.
Typically: 45 amp Finecuts work best from 26 gauge to 10 gauge, 45 amp shielded work best from 10 gauge to 1/4" (to 1/2" if your plasma only goes to 45 amps), 65 amp shielded are best used from 1/4" through 5/8" , and 85 amps from 1/2" through 3/4". Each of these consumable sets will cut thicker than I suggest if you start on an edge. The upper limits listed here are the maximum recommended piercing capability for each power level.
Voltage is height, higher voltage, higher height. Amperage is relative cutting power, higher amperage = thicker and faster.
Jim Colt Hypertherm
jhsenterprises wrote:Awesome thanks for the explanation on voltage. What about the amps? Why do some people run lower amps, and what does this actually do?