... and PNP), Proximity Switch IHS is backup for Torch Retaining Cap IHS for cutting dirty/rusty workpiece ... or Manual mode, when torch head touches the workpiece, THC automatically lift torch up to IHS height. ... XPTHC-300, user no need to worry about torch head crashing.C, Freeze Auto Height Control on Corner ... 30V, THC Auto Control Mode freezes to avoid torch head diving, until it goes back to 30V range ...