Controls And Settings - Lincoln LN-742 Service Manual

B-3
• 0.045 to 5/64 in. (1.2 to 2.0 mm) cored wire for
Innershield processes.
The LN-742H is capable of the following wire feed
ranges:
• 0.025 to 0.045 in. (0.6 to 1.2 mm) solid wire for gas-
metal-arc or CV submerged arc processes.
• 0.045 in. (1.2 mm) cored wire for Outershield gas-
metal-arc or Innershield processes.

CONTROLS AND SETTINGS

The operator controls are located on the keypad
shown in Figure B.1. The keypad consists of: 7
membrane keys with tactile-feel embossed domes,
that are generously spaced to provide easy selection,
even while wearing welding gloves; a long-life, 3-1/2
digit, 7 segment LED display with 0.56 in. (14.2 mm)
character height, permitting easy viewing even from
long gun cable distances; and high intensity, red, LED
indicator lights that allow for viewing at almost any
angle.
TRIGGER MODE CONTROLS. This control enables
the operator to choose the mode of operation as
shown by the indicator lights. Pressing the key causes
the mode lights to sequence (from top to bottom). The
top light indicates standard (two-step) trigger mode. In
COLD
INCH
KEY
SETTING
ADJUSTMENT
ARROW KEYS
TRIGGER
MODE
CONTROLS
OPERATION
FIGURE B.1 – WIRE FEEDER CONTROLS.
COLD INCH GAS PURGE
OLTMETER
INCH
WFS
TRIGGER MODE TIME
PREFLOW POSTFLOW
t1
STD t2
t
LOCK BURNBACK
t
SPOT SPOT
t
LN-742 & LN-742H
this mode the unit will only be active when the trigger
is pressed. The middle light indicates lock (four-step)
trigger mode. In this mode the solenoid is energized
when the trigger is pressed, the power source and
wire feeder are energized after preflow time when the
trigger is released. Closing the trigger a second time
turns off the wire feeder and then the power source
after burnback time. Releasing the trigger a second
time turns off the solenoid after Burnback time. The
bottom light indicates spot weld trigger mode. Closing
the trigger allows a single, timed, weld cycle. The
duration of the weld cycle is set with the time selection
controls. The spot on timer starts when welding
current flows.
TIME SELECTION CONTROLS. This control enables
the operator to choose which timer will be displayed as
shown by the indicator lights. Pressing the key causes
the mode lights to sequence (from top to bottom). Any
timers not available to the currently selected mode will
be skipped. Times displayed in the LED display are
adjusted using the setting adjustment arrows to the left
of the LED display. The top left light indicates the
preflow time is being displayed in seconds. The top
right indicator light indicates the postflow time is being
displayed in seconds. The middle light indicates the
burnback time is being displayed in seconds. The
bottom light indicates the spot weld time is being
displayed in seconds.
GAS
PURGE
KEY
LED
DISPLAY
FUNCTION
SELECTION
CONTROLS
TIMER
SELECTION
CONTROLS
B-3