Setting Run-In Speed On Standard Power Mig Feeder; Fast Or Slow Run-In Mode Selection (When Timer Option Is Not Installed; Instructions To Enter Slow Run-In; Instructions To Enter Fast Run-In - Lincoln Electric POWER MIG SVM170-A Service Manual

B-8
SETTING RUN-IN SPEED ON STAN-
DARD POWER MIG FEEDER
FAST OR SLOW RUN-IN MODE
SELECTION,
(When Timer Option is not installed)
The POWER MIG 255C is factory set for fast run-in
mode where the wire feed will accelerate directly to the
preset wire feed speed when the gun trigger is closed.
Slow run-in mode may also be selected, where it will
initially feed wire at 50 IPM until output current is
sensed or for 1.0 seconds, whichever occurs first. After
which it will accelerate to the preset wire feed speed.
Note: See operating instructions for Timer Option Kit
if it is installed, as it provides its own Run-in operation.
INSTRUCTIONS TO ENTER SLOW
RUN-IN
1. Turn power OFF on front panel of POWER MIG
255C.
2. Turn the wire feed speed dial to minimum, fully coun-
terclockwise.
3. With the gun trigger closed, turn the power ON at
the front panel of the POWER MIG 255C.
4. The display will read "SLO run".
INSTRUCTIONS TO ENTER FAST
RUN-IN
1. Turn power OFF on front panel of POWER MIG
255C.
2. Turn the wire feed speed dial to maximum, fully
clockwise.
3. With the gun trigger closed, turn the power ON at the
front panel of the POWER MIG 255C.
4. The display will read "FAS run".
NOTE:Arc starting characteristics may be effected
when using the fast run-in mode since optimum start-
ing processes are being overridden.
On the initial trigger closure at power up, no output
power or wire feed will be available until the trigger is
opened and reclosed, regardless of wire feed speed
dial setting.
It is not necessary to repeat either of the above
procedures each time the unit is powered up. The unit
will remember the run-in mode from the previous
OPERATION
power down and return you to that same state upon
your next power up. Thus, you need only perform one
of the above procedures when you want to change the
run-in mode.

MAKING A WELD

1. Check that the electrode polarity is correct for the
process being used, then turn the power switch ON.
2. Set desired arc voltage and wire speed for the
particular electrode wire, material type and
thickness, and gas (for GMAW) being used. Use the
Application Chart on the door inside the wire
compartment as a quick reference for some
common welding procedures.
3. If Timer Kit is installed, select the desired mode as
described in "Operating Instructions for Timer Kit" in
the Accessories section. Refer to the Accessories
section for additional welding information pertaining
to Spot mode. That chart is also in this manual as
Figure B.5.
4. Press the trigger to feed the wire electrode through
the gun and cable and then cut the elec-trode within
approximately 3/8" (10 mm) of the end of the
contact tip [3/4" (20 mm) Outershield
NOTE: If set for slow run-in when the trigger is pulled,
the wire feeder feeds wire at low speed regardless of
the set wire feed speed until the welding arc starts or
1 second has elapsed. This feature enhances starting
and makes it easier to set the stickout. The 1 second
limit permits high speed loading of the gun and cable.
To change run-in mode, see "Setting Run-In Speed"
in this section, if the Timer Kit is not installed, or Timer
Kit Operation section if installed.
5. If welding gas is to be used, turn on the gas supply
and set the required flow rate (typically 25-35 CFH;
12-16 liters/min).
6. When using Innershield electrode, the gas nozzle
may be removed from the insulation on the end of
the gun and replaced with the gasless nozzle. This
will give improved visibility and eliminate the
possibility of the gas nozzle overheating.
7. Connect work cable to metal to be welded. Work
clamp must make good electrical contact to the
work. The work must also be grounded as stated in
"Arc Welding Safety Precautions".
POWER MIG 255C
B-8
®
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