Plasma torch control system controls torch height

April 18, 2012

Plasma torch control system controls torch height -

ESAB Cutting Systems offers the new Smart Voltage Height Control (SVHC) system, which automatically compensates for electrode wear in plasma cutting.

The system uses the company's PB-MB-1 plasma torch station and integrates capabilities from the company's arc voltage sample and hold feature and patented electrode wear detection system. The torch station features pneumatically balanced tool-tip sensing, magnetic breakaway crash protection, and an encoder for accurate Z-axis position control.

The pneumatically balanced magnetic breakaway torch holder allows accurate initial height sensing. It is combined with an electrical touch sensor that also detects when the torch is in contact with the plate. According to the manufacturer, this dual-sensor system provides accurate sensing of the plate surface, which is used as the reference for initial cutting height.

The encoder controls the torch height for initial piercing and cutting height. Once the torch has fired and moved down to its cutting height, the arc voltage is electronically measured and digitized. The system then switches to arc voltage height control and maintains that same voltage throughout the remainder of the cut.

By sampling and holding the voltage after every pierce, the system keeps the nozzle-to-plate distance constant throughout the life of the electrode.