Look in the User Manual at the cut charts. That will give the correct arc volts with the arc gap at .063 on different materials. If you are looking for the Arc Good signal (Arc XFR in the 1000) that signals the presence of a valid arc then the two ARC XFR ouputs on J19 are dry contacts. A valid arc is based on the arc current rather that the arc volts.
You pick up raw arc volts at J15 and J16. Open arc volts (firing in the air) is approx 160 to 180VDC. The actual volts while cutting are a function of the Arc Gap (distance from the nozzle tip to the top of the workpiece), the feedrate and the current setting of the plasma combined with the nozzle (orifice) size.