Lincoln Electric IM887 K2490-1 MAGNUM 250 LX SPOOL GUN - Manual (Page 14)

8
MAGNUM 250 LX - OPERATING INSTRUCTIONS
Making A Weld
1. Check that the spool gun power, control, and gas connections are
correct for the power source being used. Check that the gas supply
is turned on. Check wire spool for an adequate supply of wire.
2. See "Procedure Settings", below for wire feed speed and voltage
settings. Set these controls depending on the welding wire and
base metal thickness being used.
3. Connect work clamp to metal being welded. Work clamp must
make good electrical contact to the workpiece. The workpiece
must also be grounded as stated in "Arc Welding Safety
Precautions".
4. Connect power to welder and turn "ON".
5. Prepare to purge gas line by first releasing wire drive. Push wire
drive release lever to the UP position, to avoid feeding wire.
WARNING: Gun body and contact tip become electri-
cally energized when gun trigger is pressed and remain
so for several seconds after trigger is released.
6. Press and hold gun trigger for about 5 seconds to purge gas line.
If adjustable regulator or metering valve is installed, adjust gas
flow per, "Setting Gas Flow Rate".
7. Re-engage wire drive by pushing release lever to down position
to feed wire.
8. Momentarily squeeze trigger and verify that wire feeds properly.
Trim wire to approximately 1/4" (6 mm) from end of contact tip.
WARNING: When using an open arc process, it is neces-
sary to use correct eye, ear, head, and body protection.
9. Position gun over joint at 10° pushing angle. End of wire may be
lightly touching the work.
10. Lower welding helmet, close gun trigger, and begin welding.
Hold the gun so that the contact tip to work distance is about 1/2
inch (13 mm).
11. To stop welding, release the gun trigger and then pull the gun
away from the work after the arc goes out.
12. When no more welding is to be done, close valve on gas cylinder,
momentarily operate trigger to release gas pressure in line and
turn off power source.
13. Note that clogged tips can often be salvaged by peeling away
melted wire.
Procedure Settings
The following procedure settings for 4043 aluminum wire and argon
gas can be used as starting points for developing specific welding
procedures:
Wire Metal Wire Amps
Size Thickness Speed DC
in. (mm) ga. in. (mm) Arc Volts ipm (mpm) (+}
.030 (0.8) 22 .030 (0.8) 13-14
(1)
200 (5.1) 40
20 .036 (1.0) 13-14
(1)
240 (6.1) 40
18 .048 (1.2) 14-15
(1)
290 (7.4) 50
16 .060 (1.6) 15-16
(1)
340 (8.6) 60
14 .075 (2.0) 16-17
(1)
370 (9.4) 70
12 .105 (2.5) 16-18
(1)
430 (10.9) 90
10 .135 (3.5) 24-26 460 (11.7) 110
3/16 (5.0) 24-26 500 (12.7) 150
1/4 (6.0) 28-29 560 (14.2) 180
3/8 (10.0) 28-30 600 (15.2) 200
.035 (0.9) 22 .030 (0.8) 13-14
(1)
150 (3.8) 40
20 .036 (1.0) 13-14
(1)
175 (4.4) 40
18 .048 (1.2) 13-14
(1)
215 (5.5) 50
16 .060 (1.6) 14-16
(1)
250 (6.4) 60
14 .075 (2.0) 14-16
(1)
270 (6.9) 70
12 .105 (2.5) 16-18
(1)
320 (8.1) 90
10 .135 (3.5) 24-26 410 (10.4) 110
3/16 (5.0) 24-26 450 (11.4) 150
1/4 (6.0) 26-28 530 (13.5) 180
3/8 (10.0) 26-29 560 (14.2) 200
1/2 (12.0) 26-30 600 (15.2) 220
3/64(1.2) 10 .135 (3.5) 20-21
(1)
180 (4.6) 110
3/16 (5.0) 20-21
(1)
220 (5.6) 150
1/4 (6.0) 27-28 250 (6.4) 180
3/8 (10.0) 25-30 260 (6.6) 200
1/2 (12.0) 25-31 270 (6.9) 220
3/4 (20.0) 25-31 290 (7.4) 250
(1) Short arc transfer.
Setting Gas Flow Rate
Gas handling systems having adjustable flow valves should be
set for the following argon flow rates, depending on base metal
thickness and welding position.
ARGON SHIELDING GAS FLOW RATES
Material Thickness Flow Rates
In Inches and (mm) Welding Position In cf/hr (l/mln)
1/16 (1.6 mm) Flat 30
(11.8)
3/32 to 3/16 Flat, Vertical, 35
(2.4 to 4.8 mm) Horizontal, Overhead (14)
1/4 to 3/8 Flat, Vertical, 35 (14)
(6.3 to 9.5 mm) Flat Vertical, 35 (16.5)
Horizontal, Overhead 40 (18.9)
3/4 (19 mm) Flat, Vertical 35 (16.5)
Horizontal, Overhead 40 (18.9)