Lincoln Electric IM10154 SAE-300 HE - Manual (Page 21)

D-2 MAINTENANCE D-2
Replace brushes when they wear within 1/4” of the
pigtail. A complete set of replacement brushes should
be kept on hand. Lincoln brushes have a curved face
to fit the commutator. Have an experienced mainte-
nance person seat these brushes by lightly stoning
the commutator as the armature rotates at full speed
until contact is made across the full face of the brush-
es. After stoning, blow out the dust with low pressure
air.
To seat slip ring brushes, position the brushes in
place. Then slide one end of a piece of fine sandpaper
between slip rings and brushes with the coarse side
against the brushes. With slight additional finger pres-
sure on top of the brushes, pull the sandpaper around
the circumference of the rings - in direction of rotation
only - until brushes seat properly. In addition, stone
slip ring with a fine stone. Brushes must be seated
100%.
Arcing or excessive exciter brush wear indicates a
possible misaligned shaft. Have an authorized Field
Service Shop check and realign the shaft.
IDLER MAINTENANCE
Before doing electrical work on the idler printed
circuit board, disconnect the battery.
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When installing a new battery or using a jumper bat-
tery to start the engine, be sure the battery polarity is
connected properly. The correct polarity is negative
ground. Damage to the engine alternator and the
printed circuit board can result from incorrect connec-
tion.
1. Proper operation of the idler requires good ground-
ing of the printed circuit board, reed switch, and
battery. Engine control unit, current sensing printed
circuit board.
2. If desired, the welder can be used without automat-
ic idling by setting the “Idler” switch to the “High”
position.
NAMEPLATES
Whenever routine maintenance is performed on this
machine - or at least yearly - inspect all nameplates
and labels for legibility. Replace those which are no
longer clear. Refer to the parts list for the replace-
ment item number.
SAE-300 ® HE
CAUTION