Lincoln Electric NA-5S Welding System User Manual


 
MAINTENANCE
D-3D-3
NA-5
The 1/8 amp fast-blow fuse, shown in Figure
D.3, on a voltage PC board built since 1983,
protects the NA-5 circuitry from damage
which may result from a ground or case
faulted control lead. If the fuse blows, the
NA-5 voltage sensing lead circuit will be
opened (Refer to
Automatic Shutdown
in
Section B, Operating Procedures) and the
Troubleshooting Guide.
FIGURE D.3 – VOLTAGE BOARD FUSE
LOCATION.
GROUND FAULT FUSE
PROTECTION
A 1/8 amp fast-blow fuse, shown in Figure
D.3, is located on the voltage PC board.
This fuse will protect the NA-5 circuitry from
damage resulting from a ground or case
faulted control lead when the arc voltage
potential exists between ground and the
NA-5 circuit common (#510). Such a
condition typically exists when the NA-5
polarity connections are set for electrode
negative.
WELDING HEAD
WIRE DRIVE GEAR BOX
Once a year, recoat all gear teeth with a
non-fluid molydisulfide type grease such as
Non-Fluid Oil Corporation’s A-29 Special/MS
Lubricant. For access to the gears in the first
chamber, remove the adapter plate and
motor assembly as shown in Figure D.4.
FIGURE D.4 – WIRE DRIVE MOTOR
GEAR BOX.
To lubricate the gears in the second
chamber, remove one of the pipe plugs and
feed grease until it comes in contact with the
bevel gear teeth. Then, rotate the output
shaft by hand until all teeth are lubricated.
1/8 AMP
FAST-BLOW
FUSE
NA-5
VOLTAGE
HEX HEAD
SCREW
ADAPTER 
PLATE AND 
MOTOR
ASSEMBLY
FIRST
CHAMBER
WIRE DRIVE
GEARBOX
SECOND
CHAMBER
SLOT HEAD
SCREW
PIPE
PLUG
DRIVE MOTOR 
BRUSH ACCESS
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