I have observed that when I first start cutting material, the voltage present on the torch starts out very high. Eventually, it will “settle” to a value that I would expect the the material thickness and torch height. For example starting at 175V and eventually decreasing to 110V. I suspect that the work clamp circuit is exhibiting some kind of higher resistance that eventually reduces to something lower. I have been attempting to ensure the clamp make a good low resistance contact on the material being cut, but this phenomenon ALWAYS occurs for me. Has anyone else observed this type of voltage shift?
I cut nothing but 16 gauge steel. My pierce height and cutting height are the same..If you start the cut too high,giving you the high voltage, then the THC needs to ramp down to the cut height..
I run my voltage at 90.
As for your clamp, I removed my clamp long ago and just use the brass eyelet that the cable has on the end of it..I drill a 5/16 hole in the steel, grind the steel down with a grinder with a flapper disc on it..And then bolt the eyelet to the steel with a nut and bolt..
That eliminates any variances that a clamp can have..
If there is a weak connection at a clamp, it can effect your THC because of resistance issues..