PROCESS AND INSTALLATION FOR AUTOMATICALLY STARTING A PLASMA WELDING TORCH

摘要

The invention relates to a plasma cutting plant comprising a principal generator feeding a plasma arc between a workpiece and an electrode of a torch comprising a tube, with initial ignition by means of an ignition or striking arc between the electrode and the tube, via the resistor and the contactor. A circuit comprising a resistor and an excitation coil of a relay is installed across the terminals of the contactor. When the torch has been brought to the correct distance from the workpiece, the circuit detects this correct spacing and acts on the feed motor to stop the latter immediately.