Setting For Cv Or Cc Power Sources - Lincoln Electric LN-8 SVM132-A Service Manual

B-6
7. Install the large ingoing guide into the rear brass
block and tighten the locking screw.
8. Install the outgoing guide tube with its plastic
insert through the front brass block. Tighten the
locking screw so the dog point goes into the
groove on the O.D. of the guide tube.
9. Set the drive roll spring pressure:
a. For wire sizes from 0.030 thru 0.052 in. (0.8
thru 1.3 mm) – With wire in the system, the
idle roll pressure indicator should be set to the
wire size shown on the "solid" side of the
nameplate. (For 0.030 in. (0.8 mm) solid wire,
set the pressure indicator to slightly less than
the 0.035 in. (0.9 mm) marking.) This setting
is a starting point and may have to be
changed depending upon the type of wire,
surface condition, lubrication, and hardness.
The optimum idle roll setting can be deter-
mined when there are wire stoppages. If the
wire "bird nests" between the drive roll and
the guide tube, the idle roll spring pressure is
too high. When properly set, the drive rolls will
slip during a stoppage. If the electrode is
removed from the cable, there will be a slight
waviness in the electrode for about a foot
beyond the slip marks on the electrode. If
there is no waviness, the pressure is set too
low.
b. For 1/16 in. (1.6 mm) solid or 0.062 in.
(1.6 mm) cored wire (using the 1/16 in. drive
roll) The idle roll pressure should be set with
wire in the system. For 1/16 in. (1.6 mm)
solid wire, the indicator should be lined up
with the "solid" 1/16 in. mark. For 0.062 in.
(1.6 mm) cored wire, adjust the idle roll pres-
sure so that the indicator is lined up with the
"cored" 3/32 in. mark.
NOTE: These indicator settings are accurate enough
so that there is no need to readjust unless the elec-
trode is unusually soft.
OPERATION
c. For wire sizes from 0.068 thru 0.120 in. (1.7
thru 3.0 mm) Idle roll pressure should be set
with wire in the system. For solid wire, the
indicator should be lined up with the "solid"
wire settings. For cored wire, the indicator
should be lined up with the "cored" wire set-
tings. When using 7/64 in. (2.8 mm) diameter
'Innershield' wire, adjust the idle roll pressure
so that the indicator is between the 0.120 and
3/32 in. "cored" wire setting.
NOTE: The indicator settings for these larger wire
sizes are accurate enough so that there is no need to
readjust, unless the electrode is unusually soft.
The drive rolls are stamped with the wire size for
which they are designed. If a wire size is used
that is not stamped on the drive roll, the drive
rolls and guide tubes will have to be changed.
SETTING FOR CV OR CC POWER
SOURCES
The LN-8N and LN-8NE weld only with a constant
voltage (CV) power source. These machines can be
converted for constant current (CC) welding by
installing the proper parts.
The LN-8S and LN-8SE weld with either a CV or CC
power source. Set the equipment for either "CV" or
"CC" as appropriate per the following:
1. If using a multi-process power source, set it up
per the instructions in the operating manual
shipped with the power source.
2. Turn the input power off and open the left panel.
Set the "CV-CC" switch located on the variable
voltage PC board inside the control box as
shown in Figure B.4.
3. There are two nameplates on top of each other
on the front of the wire feeder control box. Make
sure the correct nameplate for the power source
being used is on top.
LN-8
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