Lincoln Electric IDEALARC SP-250 Service Manual page 30

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FEEDING ELECTRODE
WARNING
When inching, the electrode and drive mechanism are
always "hot" to work and ground.
remains "hot" several seconds after the gun trigger is
released.
____________________________________
NOTE: Check that the proper drive rolls and gun parts
are used for the wire size and wire type being used.
1. Turn the Readi-Reel or spool until the free end of
the electrode is accessible.
2. While tightly holding the electrode, cut off the bent
end and straighten the first six inches. Cut off the
first inch. (If the electrode is not properly straight-
ened, it may not feed properly into the outgoing
guide tube or welding gun causing a "birdnest".)
3. Push the wire through the ingoing guide tube, then
press the gun trigger and push the electrode into
the drive roll. If the electrode fails to thread itself
into the outgoing guide tube of the wire drive, open
the quick release idle roll arm, thread the electrode
manually, and reclose the arm.
4. Inch the electrode through the gun.
NOTE: Due to the low speed starting feature of the
SP-250, the wire will feed at low speed for 2 seconds
while inching, then come up to the set speed.
5. Check that the welding process is set for the wire
type, diameter, and gas per instructions on name-
plate.
SETTING IDLE ROLL PRESSURE
The idle roll pressure wing screw is set at the factory
backed out 2fi turns from full pressure. This is an
approximate setting. The optimum idle roll pressure
varies with type of wire, wire diameter, surface condi-
tion, lubrication, and hardness. As a general rule, hard
wires may require greater pressure, and soft, or alu-
minum wire, may require less pressure than the facto-
ry setting. The optimum idle roll setting can be deter-
mined as follows:
1. Press end of gun against a solid object that is elec-
trically isolated from the welder output and press
the gun trigger for several seconds.
OPERATION
2. If the wire "birdnests", jams, or breaks at the drive
roll, the idle roll pressure is too great. Back the
wing screw out fi turn and run new wire through the
gun. Repeat above step.
3. If the drive roll slips, loosen the gun cable Fast-
The electrode
Mate connection nut from the front of the SP-250.
Pull the gun cable forward about 6". There should
be a slight waviness in the exposed wire. If there
is no waviness, the pressure is too low. Tighten the
wing screw 1/4 turn and lock the gun cable in
place. Repeat the above procedure.
IDEALARC SP-250
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