Lincoln Electric SVM194-A 54TROUBLESHOOTING and REPAIRF-54, Inspection and Service Procedure

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F-54TROUBLESHOOTING AND REPAIRF-54

WELDING GENERATOR BRUSH AND COMMUTATOR

INSPECTION AND SERVICE PROCEDURE (continued)

FIGURE F.3 - DRILL MARK LOCATIONS

EXCITER BRACKET

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DRILL MARKS

ROCKER

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PROCEDURE

1. Shut off the engine.

2. Open either, or both of the side doors of the Classic® 300 machine.

NOTE: Secure the doors in the open position using the door restraint system. If the machine does not have a door restraint system, remove the doors or securely restrain them to prevent them from falling closed.

3. Disconnect the negative battery cable.

4. Remove the cover protecting the welder gener- ator brushes.

Examine the Commutator:

Normal appearance:

The commutator should appear smooth, and have an even brown color where the brushes ride.

Blackened Commutator:

A commutator that appears an even black color all around may indicate a grounded armature, shorted weld circuit, a serious overload condition, or out-of- adjustment rocker. It could also indicate the use of poor quality brushes, or brushes that have been contaminated with oil or some other foreign sub- stance.

• Check the rocker position. Be certain that it is aligned with or very close to the factory drill mark. See Figure F.3. IMPORTANT: If the rocker position requires adjustment, do not over tighten the rocker clamping screw. This screw should be tightened to a torque of 70 to 75 Inch-Lbs. Over tightening can destroy the rocker.

• Perform the Weld Circuit Ground and Short

Circuit Test.

• If the weld circuit is not grounded or shorted, and poor brush quality or contamination is suspect- ed, replace the brushes and seat them with a commutator stone or sand paper.

• If brush quality or contamination is not suspect- ed, clean the commutator by lightly stoning the surface. See caution note on commutator stone use.

CLASSIC® 300D & 300G