Lincoln Electric Pro-MIG 140 manual Component Replacement Procedures, Changing the Contact TIP

D-3 MAINTENANCE D-3

COMPONENT

REPLACEMENT

PROCEDURES

CHANGING THE CONTACT TIP

1.Refer to Figure D.2. Remove the gas nozzle from the gun by unscrewing counter-clockwise.

2.Remove the existing contact tip from the gun by unscrewing counter-clockwise.

3.Insert and hand tighten desired contact tip.

4.Replace gas nozzle.

CHANGING DRIVE ROLL

The drive roll has two grooves; one for .023" – .025" (0.6 mm) solid steel electrode and a larger groove for

.030" (0.8 mm) solid and .035" (0.9 mm) flux-cored steel electrode. As shipped, the drive roll is installed in the .035" (0.9 mm) position.

If .023"/.025" (0.6 mm) wire is to be used, the drive roll must be reversed as follows:

1.Connect the machine to its rated input power per instructions in Installation section.

2.Release the spring-loaded idle arm tensioner,Item 2, and lift the idle roll arm, Item 3, away from the drive roll, Item 1. (See Figure D.1)

3.Turn the power switch to ON (marked “I”).

4.Set the wire speed to minimum and jog the drive unit with the trigger switch until the drive roll set screw is facing up.

CAUTION

When inching the welding wire, the drive rolls, gun connector block, and gun contact tip are energized relative to work and ground and remain energized for several seconds after the gun trig- ger is released.

5.Turn the power switch to OFF (marked “O”).

6.Loosen the drive roll set screw with the 5/64" (2.0 mm) hex wrench supplied.

7.Remove the drive roll, flip over and reinstall with the

.023"/.025" (0.6 mm) groove (the smaller groove) closest to the gearbox.

8.Push a length of straightened welding wire through the wire feeder guide tubes and adjust the position of the drive roll so that the groove is centered on the wire. Make certain the set screw is located on the flat portion of the shaft and tighten.

FIGURE D.1

3

2

1

Pro-MIG 140