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.