Lincoln Electric SVM104-A service manual Theory of Operation, Pilot ARC

		THEORY OF OPERATION	E-4
Return to Section TOC	Return to Master TOC	FIGURE E.5 - Pilot Arc
Return to Section TOC	Return to Master TOC

		PILOT ARC	nozzle to the electrode in the torch head and then
TOC	TOC		on to the torch bulkhead connector, which is con-
		The Pro-Cut 60 has a smooth, continuous pilot	nected to the negative potential within	the
			machine. When the torch head is brought close to
Section	Master	arc. The pilot arc is a means of establishing and
			surface and the cutting arc is established.	This
		The pilot arc current flow is from the positive
		transferring the arc to the work piece for cutting.	the work piece the pilot arc transfers to the work
to	to	potential work terminal through the R2 resistor	transition takes place because of the low resis-
Return	Return	and CR2 contacts to the pilot lead circuit in the	tance between the torch electrode and the work
			piece.
		torch cable. The pilot current transfers from the

to Section TOC	to Master TOC
Return	Return
		FIGURE E.6 - Pilot Lead Circuit

NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion	PRO-CUT 60