Gun And Cable Installation; Shielding Gas; Auxiliary Power Receptacles - Lincoln Electric POWER MIG SVM170-A Service Manual

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GUN AND CABLE INSTALLATION

The Magnum 250L gun and cable provided with the
POWER MIG 255C is factory installed with a liner for
0.035-0.045 in. (0.9-1.2 mm) electrode and an 0.035
in. (0.9 mm) contact tip. Install the 0.045 tip (also pro-
vided) if this wire size is being used.
WARNING
Turn the welder power switch off before installing
gun and cable.
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1. Lay the cable out straight.
2. Unscrew knurled screw on the drive unit front end
(inside wire feed compartment) until tip of screw
no longer protrudes into gun opening as seen
from front of machine.
3. Insert the male end of gun cable into the female
casting through opening in front panel. Make sure
connector is fully inserted and tighten knurled
screw.
4. Connect the gun trigger connector from the gun
and cable to the mating receptacle inside the
compartment located above the gun connection
made in item 3 above. Make sure that the key-
ways are aligned, insert and tighten retaining ring.

SHIELDING GAS

(For Gas Metal Arc Welding Processes)
Customer must provide cylinder of appropriate type
shielding gas for the process being used.
A gas flow regulator, for CO 2 or Argon blend gas, and
an inlet gas hose are factory provided with the POWER
MIG 255C. Install the shielding gas supply as follows:
1. Set gas cylinder on rear platform of POWER MIG
255C. Hook chain in place to secure cylinder to
rear of welder.
2. Remove the cylinder cap. Inspect the cylinder
valves and regulator for damaged threads, dirt,
dust, oil or grease. Remove dust and dirt with a
clean cloth.
DO NOT ATTACH THE REGULATOR IF OIL,
GREASE OR DAMAGE IS PRESENT! Inform
your gas supplier of this condition. Oil or grease
in the presence of high pressure oxygen is
explosive.
INSTALLATION
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3. Stand to one side away from the outlet and open
the cylinder valve for an instant. This blows away
any dust or dirt which may have accumulated in
the valve outlet.
Be sure to keep your face away from the valve out-
let when "cracking" the valve.
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4. Attach the flow regulator to the cylinder valve and
tighten the union nut(s) securely with a wrench.
NOTE: If connecting to 100% CO 2 cylinder, insert
regulator adapter between regulator and cylinder
valve. If adapter is equipped with a plastic washer, be
sure it is seated for connection to the CO 2 cylinder.
5. Attach one end of the inlet gas hose to the outlet
fitting of the flow regulator, the other end to the
POWER MIG 255C rear fitting, and tighten the
union nuts securely with a wrench.
6. Before opening the cylinder valve, turn the regu-
lator adjusting knob counterclockwise until the
adjusting spring pressure is released.
7. Standing to one side, open the cylinder valve
slowly a fraction of a turn. When the cylinder pres-
sure gauge pointer stops moving, open the valve
fully.
Never stand directly in front of or behind the flow
regulator when opening the cylinder valve. Always
stand to one side.
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8. The flow regulator is adjustable. Adjust it to the
flow rate recommended for the procedure and
process being used before making the weld.

AUXILIARY POWER RECEPTACLES

(For 208/230V Models only)
This machine is equipped with 15Amp 120V receptacle with
15Amp Circuit Breaker. The receptacle is UL and CSA
approved.
POWER MIG 255C
WARNING
CYLINDER may explode if
damaged.
• Gas under pressure is explosive. Always keep
gas cylinders in an upright position and always
keep chained to undercarriage or stationary
support. See American National Standard Z-
49.1, "Safety in Welding and Cutting" pub-
lished by the American Welding Society.
WARNING
WARNING
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