Well, made my first cuts with the Pro yesterday and I am more than pleased. I was cutting 16 gauge hot rolled with the Razorweld 45 at 30 amps. My nominal voltage was right in the 113.4 range. THC appeared to work exactly as designed. Question…. What would be “normal” arc voltage? Should I expect it to change with varying thicknesses / types of metal and / or amperage? Also…. If it can be explained simply, what exactly is the “arc voltage” and how does it differ from the amp setting of the plasma cutter.
Awesome to hear. I 've had my Pro since November and have been enjoying it very much.
Nominal Arc voltage listed on your cut charts as Voltage in volts is determined at the manufacture’s testing stage. The manufacturer sets up repeatable test scenarios to provided the best quality of or best production cut . From these tests they prove their engineered math and populate the cut charts for our use. So we do not have to guess at the voltage’s value or use a system like SMART voltage to set it for us.
On this cut chart page 113 out of the service manual
shows the voltage target as 125 volts @ 45amps
very close to what your SMART voltage registered at 113.4 volts @ 30amps
Yes, Changes to Resistant or Amperage will effect the Voltage.
Your machine wants to maintain the Amperage that it is set for.
The Voltage is only measured by us and used to tell the THC how to act.
Arc Voltage is the difference in potential between two points in a circuit that contains an Arc. Pressure.
Attached is a Clip from Page 345 of the service manual
the points for raw arc voltage J22 and J9. This is one place where this potential difference could be measured
Also shows J17 to the voltage divider then out the CPC.
port this is where the Langmuir measures its voltage from.
They are two separate measurements.
Voltage. Potential Difference or Pressure of the Circuit
Amperage. Volume of Electrons
As a side note under the the THC Settings it notes the " *SMART Voltage only for 14ga and thicker"
Attached screen shots from Fire Control .
I’ve been trying to run close to book cut chart and I’ve been entering my nominal voltage when set to 45amps.
Also a note reaffirming that voltage is condition dependent from the 45xp service manual.
Links
Powermax45 XP Service Manual (809230 revision 2)
To answer the title Question " What is “good” arc voltage?"
The one that produces a repeatable cut in quality for all the repeatable variables.
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Thanks for a great explanation! Your reply was well worth the read:+1:
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Hey Brian check out these 2 videos from D & N Custom Creations they are very good.
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Thank you very much for your detailed response. As with anything, I think the more I get to understand how this works, it will make troubleshooting that much easier if (when) the time comes. Thank you again!
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Thank you very much for forwarding these videos. This guy did a great job explaining how the system works. Thank you again!
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I think its important to note that the cut chart you posted was from a Hypertherm, not a Razorweld. I was trying to figure out why it was different from the official Razorweld cut chart, and then saw your Service Manual link was to the Hypertherm.
From my limited 2-years experience with the RW45, it seems to enjoy sitting between 110 and 120 volts. Whenever I turn SMART control off, i just use 120v.
@MotoRider42HC you’re right I should have highlighted the fact that I was using a Hypertherm as the example. I mainly picked the Hypertherm charts because they do actually have a voltage listed. I just tried to change my original post but I guess after a certain amount of time your ability to edit an old post is taken away.
@langmuir-aksel how long do you have before a post loses its ability to be edited?
Is there a chance that you could increase that amount of time to Infinity for level 3 members?
Great video and explanation.
What was the amperage you were using.
Thankyou.