Rocker Adjustment Procedure - Lincoln Electric Classic 300 MP Service Manual

LINCOLN ELECTRIC

ROCKER ADJUSTMENT 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
The Rocker is the part of the Welding Generator that supports and positions the 4 sets of Brushes. Its
position can be adjusted to fine tune the weld output and influence the weld characteristics.
IMPORTANT: The Rocker is set at the factory for the best overall performance and long Generator and
Brush life. Altering this adjustment is normally not recommended unless one or more of the Welding
Generator components affecting this setting have been replaced. In very unusual situations, very small
adjustments of the Rocker may be beneficial if the machine is operating within the specified limits, but the
arc characteristics are unsatisfactory for the desired application.
CAUTION: Improper Rocker adjustment can result in poor performance, reduced Brush life and damage to
the Welding Generator. This adjustment should only be attempted by an experienced professional.
MATERIALS NEEDED
Resistive Load Bank, Capable Of Absorbing At Least A 300 Amp Load
Voltmeter
Ammeter, Able To Read At Least 300 Amps
Miscellaneous Hand Tools
Drill with 1/8" Bit
Tachometer Or Frequency Meter
Wiring Diagram
TEST PROCEDURE
The factory set point drill marks:
1. Perform the Case Cover Removal Procedure.
2. When the rocker is set for the first time at the factory, a 1/8" drill is used to mark the position of
both the rocker and the exciter bracket.
3. If a machine is not operating within the specified limits and nothing else appears to be faulty, the
rocker position should be checked. If the drill marks are not aligned, the rocker and/or the exciter
bracket should be reset to the original factory position.
4. If it has been determined that a rocker adjustment is necessary on an unaltered machine; the rocker
should only be moved in very small increments and the total movement should be no more than 1/2
the diameter of the drill mark.
5. Setting the rocker – if the factory drill mark is missing or invalid due to component replacement.
Classic® 300 MP Service Manual
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