Security of weld procedure settings, B-12, Operating instructions – Lincoln Electric NA-5S User Manual
Page 35
OPERATING INSTRUCTIONS
B-12
B-12
NA-5
SECURITY OF WELD
PROCEDURE SETTINGS
There are two means provided to prevent or
limit unauthorized readjustment of the NA-5
voltage and wire feed speed controls once
set to the desired procedure.
1. The security panel of the NA-5 can be
locked to prevent access to the
control knobs.
2. The control range of the procedure
control knobs can be limited to either
about 3% or about 15% of the full
range control by installing a knob
rotation stop screw to any or all of the
control knobs. This stop screw is
installed in the following manner:
a. Turn off the input power to the
NA-5.
b. Loosen each knob set screw and
remove all knobs, including the
rotary select switch knob.
c. Remove the felt seal and square
spacer tube mounted behind
each control knob.
d. Open the control box.
Disconnect, then remove, the
procedure control PC board
assembly and its panel insulation.
e. Install a 1/2 in. long, pan or round
head, #4 sheet metal screw into
the 0.10 in. diameter hole located
beneath each square so the head
is on the back side of the panel
(inside the control box).
f.
Remount the PC board assembly
and its panel insulation.
Reconnect the PC board and
close and secure the control box.
g. Remount the rotary select switch
knob and replace each square
spacer tube and felt seal so the
#4 screw protrudes between the
tube and the felt seal.
h. Turn on the NA-5 input power and
set the desired procedure by
rotating the shafts of the controls.
i.
Carefully replace each control
knob so the #4 screw inserts into
the center of the shorter length
channel on the back of the knob
for about 3% of the total range of
control or into the center of the
longer length channel for about
15% of the total range of control.
j. With finger pressure on the knob
against the felt seal, carefully
retighten the set screw of each
knob.
NOTE:
Steps h thru j will have to be
repeated if it is desired to change the
procedure settings to values outside the
selected 3% or 15% control range limit.