Lincoln Electric SAE-300 HE, Service Manual, Page: 40 / 84

LINCOLN ELECTRIC SAE-300® HE Service Manual
35
WELDING GENERATOR BRUSH AND COMMUTATOR INSPECTION AND SERVICE
PROCEDURE
Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized
repairs performed on this equipment may result in danger to the technician or machine operator and will
invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety
notes and precautions detailed throughout this manual. If for any reason you do not understand the test
procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department
for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
TEST DESCRIPTION
This procedure provides guidelines for checking and servicing the Welding Generator Commutator and
Brushes.
MATERIALS NEEDED
120-150 Grit Commutator Stone
220-320 Grit Commutator Stone
Wiring Diagram
IMPORTANT: Do not use emery cloth to clean the commutator. Use only sandpaper or a commutator
stone.
CAUTION: Stoning the commutator involves pressing an abrasive stone against a spinning commutator.
This procedure can be hazardous if done without proper training, tools and protective equipment. Consult
the commutator stone manufacturer’s instructions before attempting this procedure.
TEST PROCEDURE
1. Turn off the engine on the SAE-300 HE machine.
2. Open either, or both of the side covers and secure them with the hooks provided.
3. Disconnect the negative battery cable. See Wiring Diagram.
4. Remove the sheet metal cover protecting the welder generator brushes.
5. Examine the Commutator.
Normal appearance:
6. The commutator should appear smooth and have an even brown color where the brushes ride.
Blackened Commutator:
7. A commutator that appears to have 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 substance.
• Check the rocker position. Be certain that it is aligned with or very close to the factory drill mark.
See Figure F.11 . 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