Lincoln Electric IM637-A manual Pilot ARC Discussion, Procedure Recommendations

B-6 OPERATION B-6

PILOT ARC DISCUSSION

The PRO-CUT has a smooth, continuous pilot arc. The pilot arc is only a means of transferring the arc to the workpiece for cutting. Repeated pilot arc starts, in rapid succession, is not recommended as these starts will generally reduce consumable life. Occasionally, the pilot arc may sputter or start intermittently. This is aggravated when the consumables are worn or the air pressure is too high. Always keep in mind that the pilot arc is designed to transfer the arc to the work- piece and not for numerous starts without cutting.

When the pilot arc is started, a slight impulse will be felt in the torch handle. This occurrence is normal and is the mechanism which starts the plasma arc. This impulse can also be used to help troubleshoot a "no start" condition.

PROCEDURE RECOMMENDATIONS

When properly used, plasma arc cutting or gouging is a very economical process. Improper use will result in a very high operating cost.

General - In All Cases

•Follow safety precautions as printed throughout this operating manual and on the machine.

Thin Gauge Sheet Metal:

Torch Standoff Machine Output Setting

45

DRAG thru 1/16"	Output Setting
Standoff	Min. Range thru 45 Amps

1.Output set below 45 amps.

•The nozzle may be dragged on the metal sur- face, touching it lightly to the surface after pierc- ing a hole. Current control should be set below the mid range.

Thick Sections of Metal

Torch Standoff Machine Output Setting

45

1/8" thru 3/16"	Output Setting
Standoff	45 Amps thru Max. Range

1.Output set above 45 amps.

•The best quality and consumable life will be obtained by holding the torch off the surface about 3/16". Too long an arc may compromise cut quality and consumable life. The nozzle should NOT be dragged on the work.

2.The nozzle should not be dragged on the work surface.

•Dragging the nozzle on the work surface will result in shortened consumable life

•Use of the S22151 Drag Cup will maintain the proper standoff and eliminate nozzle double arcing.

•If piercing is required, slowly lower the torch at an angle of about 30° to blow the dross away from the torch tip and slowly rotate the torch to a vertical position as the arc becomes deeper. This process will blow a lot of molten metal and dross. Be careful! Blow the dross away from the torch, the operator and any flammable objects.

•Where possible, start the cut from the edge of the work piece.

•Keep moving! A steady speed is necessary. Do not pause.

•Do not allow torch cable or body to contact hot surface.

2.Current Control should be set below the mid range.

•Do not allow cable or body to contact hot sur- face.

PRO-CUT 55