Lincoln Electric IM812-A - Manual (Page 19)

D-1 MAINTENANCE D-1
LN-35
SAFETY PRECAUTIONS
Have qualified personnel do the maintenance
work. Turn the engine off before working inside
the machine. In some cases, it may be
necessary to remove safety guards to perform
required maintenance. Remove guards only
when necessary and replace them when the
maintenance requiring their removal is
complete. Always use the greatest care when
working near moving parts.
Do not put your hands near the engine cooling
blower fan. If a problem cannot be corrected by
following the instructions, take the machine to
the nearest Lincoln Field Service Shop.
ELECTRIC SHOCK can kill.
• Do not operate with covers removed.
• Do not touch electrically live parts or
electrode with skin or wet clothing.
• Turn the input power to the welding power source
off at the fuse box before working in the terminal
strip.
• Insulate yourself from work and ground
• Always wear dry insulating gloves.
See additional warning information
throughout this operator ’ s manual and
the Engine manual as well.
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WARNING
ROUTINE MAINTENANCE
DRIVE ROLLS AND GUIDE TUBES
After feeding every coil of wire, inspect the drive roll
section. Clean it as necessary. Do not use a solvent
for cleaning the idle roll because it may wash the lu-
bricant out of the bearing. The drive roll, idle roll and
guide tubes are stamped with the wire sizes they will
feed. If a wire size other than that stamped on the rolls
is to be used, the rolls and guide tubes must be
changed.
The drive rolls for .035 through .052 cored electrode
and 1/16 through 5/64 electrode have a double set of
teeth so they can be reversed for additional life. Drive
rolls for .023 through .052 solid electrode and
aluminum sizes have no teeth but use two grooves so
they also can be reversed for additional life.
See Wire Feed Drive Roll and Guide Tube Kits Sec-
tion for roll changing instructions.
WIRE REEL SPINDLE
No routine maintenance required. Do not lubricate
spindle.
CONTROL BOX
Every six months open and inspect the control sec-
tion. The accumulated dirt should be gently blown off
all of the electrical components. Be sure the air that
is being used is dry. Check that lead plugs are secure
in their receptacles.
WIRE DRIVE MOTOR AND GEAR BOX
Every year examine the gear box. Paint the gear teeth
with molydisulfide filled grease. Lincoln specification
E2322.
Do not use a graphite grease.
Check the motor brushes. Replace if they are worn
down to 1/4 inch or less. When ordering feed motor
b r u s h e s , g i v e a l l i n f o r m a t i o n f r o m t h e motor
nameplate.
GUN AND CABLE MAINTENANCE
See IM manual provided with the gun and cable as-
sembly.
CIRCUIT PROTECTION AND
AUTOMATIC SHUTDOWN
CONTROL PC BOARD FUSE
On G1757-6 (or higher part no.) P.C. Boards the 1/8
amp fuse was replaced with electronic protection for
trigger circuit faults to electrode circuit.
On G1757-2 through -5 part no. PC boards, the 1/8
amp fuse interrupts the 500A lead to the trigger switch.
On G1757- 1 PC boards a 5 amp fuse was used to
interrupt the 667 lead. The LN-35 will not operate if
the fuse is blown.
AUTOMATIC PROTECTION SHUTDOWN
(See Automatic Protection Shutdown Section.)