Duty cycle on a powermax 1000

[copperhead10]

I am cutting parts on a 5x10 CNC table using a Powermax 1000 g3. The duty cycle on this machine is listed at 50% at 60amps, and it will shut down after a while of continuous cutting. Many of my projects call for over an hour of cutting on one sheet. I can program in breaks to let the machine cool but I am trying to balance taking all day to cut a sheet and overheating the machine mid cut and damaging a work piece by having to re pierce after a shutdown.
My questions are:
-Is there a better formula for finding the time to rest the machine than 5minute on and 5 minutes off?
-Is there any way to boost the duty cycle of this machine?
-Should I really baby this machine and stick to the 5 on 5 off rule or is there any harm in running it until it shuts down?

[jimcolt]

Duty cycle is very complicated as it involves a lot of issues related to your power input, what you are cutting (material and thickness) as well as your output amperage setting and the ambient air temperature.

First...the Powermax1000 has different duty cycle ratings depending on your input voltage. If your input line voltage feeding the Powermax1000 is between 200 and 208 volts (single or three phase) then the rated duty cycle when cutting the maximum production thickness on steel (1/2" steel being cut at 60 amps and 141 load volts) is 40%....that means that after the internal components are up to temperature....and if the ambient air temperature is 104 degrees fahrenheit...then the unit can cut 1/2" steel for 4 minutes continously with a 6 minute rest between cuts.

If it is cooler than 104 degrees in your shop...the system will have a higher duty cycle abd can cut for more than 4 minutes. If the heat sinks inside your power supply are covered with shop dust...then expect the duty cycle to be lower. If you are running at a torch height (arc length) that produces a torch arc voltage higher than 141 volts, expect the duty cycle to be lower....etc.

If your input line voltage is 230 volts or higher (most common for N. American voltages) the duty cycle rating for the Powermax1000 is 50% under the same conditions as listed above.

Since arc voltage is a part of the duty cycle equation....and cutting thicker materials requires a longer arc (higher arc voltage) ...that means the thicker you cut...the lower your duty cycle will be, thinner materials and your duty cycle will be higher.

You do not mention the temperature in your shop...or the thickness and type of material being cut...or what your incoming line voltage is. Armed with this information...I can help determine if your are close to duty cycle, exceeding it, or are below it.

To maximize the duty cycle of your plasma:

- Move it to an area that may have cooler, clean air flow...if possible.
-On a regular schedule disconnect power, remove the cover...and carefully blow all of the dust out of the unit.
-Operate at as low of an arc voltage, as low of an output amperage as possible. If cutting thinner materials, faster speeds and lower amperage will help (faster cut speeds produce a lower arc voltage).

Other fixes....a larger plasma system (such as Powermax85) operated at 65 amps output can provide 100% duty cycle. Hypertherm also has a whole line of industrial plasma systems that are 100% duty cycle under all cutting conditions.


Hope this helps...


Jim Colt Hypertherm

I am cutting parts on a 5x10 CNC table using a Powermax 1000 g3. The duty cycle on this machine is listed at 50% at 60amps, and it will shut down after a while of continuous cutting. Many of my projects call for over an hour of cutting on one sheet. I can program in breaks to let the machine cool but I am trying to balance taking all day to cut a sheet and overheating the machine mid cut and damaging a work piece by having to re pierce after a shutdown.
My questions are:
-Is there a better formula for finding the time to rest the machine than 5minute on and 5 minutes off?
-Is there any way to boost the duty cycle of this machine?
-Should I really baby this machine and stick to the 5 on 5 off rule or is there any harm in running it until it shuts down?

[Rem300wm]

Hello to all

Sorry to hijack Your tread but i have the same machine and the problem i have is that the machine will not work until 24 hours later,even if I give it the rest between cuts,it will shut down and not work for this amount of time.
Right now trying to cut 14 Ga mild steel with FineCut consumables 40 amp tips at 110 IMP. Voltage is 230 V. and temp in the shop is around 90 deg Average.


Any more suggestions to try and extend the duty cycle?

Thanks

Rem

[jimcolt]

Rem....if you hit duty cycle with a Powermax1000...it will stop the arc and keep the fan on. It generally will take no more than about 5 minutes to cool adequately. If it takes 24 hours....the problem has nothing to do with its duty cycle rating. I suggest contacting Hypertherm tech service and describe your problem in detail, they will be able to help you out.

Jim Colt

Hello to all

Sorry to hijack Your tread but i have the same machine and the problem i have is that the machine will not work until 24 hours later,even if I give it the rest between cuts,it will shut down and not work for this amount of time.
Right now trying to cut 14 Ga mild steel with FineCut consumables 40 amp tips at 110 IMP. Voltage is 230 V. and temp in the shop is around 90 deg Average.


Any more suggestions to try and extend the duty cycle?

Thanks

Rem