Lincoln Electric LF-72/74 Welder User Manual


 
LF-72/74
OPERATION
B-6 B-6
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Trigger Interlock
Trigger Interlock operation provides for operator com-
fort when making long welds. When the gun trigger is
first pulled, the welding power source energizes the
output and the wire feeder feeds wire for welding. The
gun trigger is then released while the weld is made. To
stop welding, the gun trigger is pulled again, and when
it is released the welding power source output turns off
and the wire feeder stops feeding wire.
If the arc goes out while welding with
trigger interlock operation, the elec-
trode output from the welding power
source remains energized and the
wire feeder will continue to feed wire
until the gun trigger is again pulled
and then released.
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6. WIRE FEED SPEED KNOB
The large, calibrated wire feed speed knob makes for
easy and accurate adjustment of the wire feed speed.
The knob rotates 3/4 turn. Turn the knob clockwise to
increase the wire feed speed, and counter clockwise
to reduce the wire feed speed.
The wire feed speed range is 50 to 800 in/min (1.27 -
20.3 m/min).
7. GUN RECEIVER BUSHING (K1500-2)
(K1500-2 bushing is standard on all LF-72's)
This Gun Receiver Bushing is used with Lincoln gun
connectors, also with Magnum 200/300/400 guns and
compatible with Tweco® #4).
8.
TRIGGER CONNECTOR 5-PIN AMPHENOL
This is used for connecting the MIG gun trigger. See
Installation Section for detail.
CAUTION