Lincoln Electric LN-742H - Manual (Page 16)

B-2 OPERATION B-2
• 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
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.
LN-742 & LN-742H
COLD INCH
OLTMETER
INCH
WFS
PREFLOW POSTFLOW
BURNBACK
SPOT
STD
LOCK
SPOT
TIME TRIGGER MODE
t1 t2
GAS PURGE
t
t
t
GAS
PURGE
KEY
LED
DISPLAY
FUNCTION
SELECTION
CONTROLS
TIMER
SELECTION
CONTROLS
SETTING
ADJUSTMENT
ARROW KEYS
TRIGGER
MODE
CONTROLS
COLD
INCH
KEY
FIGURE B.1 – WIRE FEEDER CONTROLS.