Lincoln Electric IM620-B manual Welding, Procedure AT END of Coil

B-8 OPERATION B-8

For CV: Set dial to the calibrated IN/MIN desired. (Refer to Setting Constant Wire Feed Speed Section.)

For CC: Set dial to value determined from the

CCWire Speed Graph for the DESIRED IN/ MIN and ARC VOLTS to be used. (Refer to Setting Arc Sensing Wire Feed Speed Section.)

NOTE: If procedure permits a range of acceptable arc voltage, use the middle of the range to

determine proper WIRE SPEED setting.

f. If using the optional Gas Flow Timer, set the de- sired PREFLOW TIME and POSTFLOW TIME.

g. Be sure the proper contact tip for the wire size being used is in the gun, and the gun is safe from work contact. (Use the LN-25 insulated gun holder.)

h. Turn on the welding power source, as well as the shielding gas supply (if used).

WARNING

Unless an optional output control or internal contactor is used, the electrode is electrically “hot” when the power source is on. The gun trigger controls wire

feed and gas supplied to the nozzle area (if used).

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WARNING

CYLINDER may explode if

damaged.

• Keep cylinder upright and chained to support.

• Keep cylinder away from areas where it may be dam- aged.

•Never lift welder with cylin- der attached

•Never allow welding elec- trode to touch cylinder.

•Keep cylinder away from welding or other live electri- cal circuits.

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WELDING

WARNING

ARC RAYS can burn.

• Do not touch metal por-

tions of the LN-25 lead Clip when welding power

source is on.

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a.Cut the electrode within approximately 3⁄8” of the end of the contact tip for solid wire and within approximately 3⁄4” of the extension guide for cored wire.

b.Position electrode over joint. End of electrode should be slightly off the work.

c.Lower welding helmet, close gun trigger, and begin welding. Hold the gun so the contact tip to work distance gives the correct electrical stickout as required for the procedure being used.

NOTE: If the arc voltage is not within the proper procedure range adjust the power source output control. (The CC mode WIRE SPEED setting should not be changed from the preset procedure value for the proper arc voltage.)

d. To stop welding, release the gun trigger and then pull the gun away from the work. Store the gun in the LN-25 insulated gun holder when not welding.

PROCEDURE AT END OF COIL

When the wire on the reel is used up, the following procedure is to be followed for removing the old wire from the gun cable and loading a new reel.

a. Shut off power source if a Remote Output Control Option or internal contactor is not used.

b.Cut the end of the electrode off at the gun end. Do not break it off by hand since this puts a slight bend in the wire and makes it difficult or impossible to pull it back through the nozzle.

c.U n c o u p l e t h e g u n c o n d u c t o r c a b l e f r o m the LN-25.

d.Lay the cable out straight.

e.Using pliers to grip the wire, pull it out of the cable from the connector end. Do not pull it from the gun end.

f.Put the conductor cable back on wire drive unit after the electrode has been removed.

g.Load a new coil of wire and feed it through the cable as described in Loading Electrode Section.

OPEN ARC WELDING WITH A CONSTANT CURRENT (formerly variable voltage) POWER SOURCE

WARNING

The LN-25 should be used with a constant current machine only upon non-critical weldments and after testing is done to assure quality is adequate for the application.

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LN-25