Operation, Wire welding-cv, Typical current ranges – Lincoln Electric IM801 RED-D-ARC GX 300 User Manual
Page 21: For tungsten electrodes, Gx 300
(1) When used with argon gas. The current ranges shown must be reduced when using argon/helium or pure helium shielding gases.
(2) Tungsten electrodes are classified as follows by the American Welding Society (AWS):
Pure
EWP
1% Thoriated
EWTh-1
2% Thoriated
EWTh-2
Though not yet recognized by the AWS, Ceriated Tungsten is now widely accepted as a substitute for 2% Thoriated Tungsten in AC and DC applications.
(3) DCEP is not commonly used in these sizes.
(4) TIG torch nozzle "sizes" are in multiples of 1/16ths of an inch:
# 4 = 1/4 in.
(6 mm)
# 5 = 5/16 in.
(8 mm)
# 6 = 3/8 in.
(10 mm)
# 7 = 7/16 in.
(11 mm)
# 8 = 1/2 in.
(12.5 mm)
#10 = 5/8 in.
(16 mm)
(5) TIG torch nozzles are typically made from alumina ceramic. Special applications may require lava nozzles, which are less prone to breakage, but cannot withstand high temperatures
and high duty cycles.
B-5
OPERATION
B-5
TIG Welding
The TOUCH START TIG setting of the MODE switch is
for DC TIG (Tungsten Inert Gas) welding. To initiate a
weld, the CONTROL dial is first set to the desired current
and the tungsten is touched to the work. During the time
the tungsten is touching the work there is very little volt-
age or current and in general, no tungsten contamination.
Then, the tungsten is gently lifted off the work in a rocking
motion, which establishes the arc.
The ARC CONTROL is not active in the TIG mode.
To STOP a weld, simply pull the TIG torch away from the
work. When the arc voltage reaches approximately 30
Volts the arc will go out and the machine will reset the
current to the Touch Start level. To reinitiate the arc, re
touch the tungsten to the work and lift. Alternatively, the
weld can be stopped by releasing the Amptrol or arc start
switch.
The GX 300 can be used in a wide variety of DC TIG
welding applications. In general the ‘Touch Start’ feature
allows contamination free starting without the use of a Hi-
frequency unit. If desired, the K930-2 TIG Module can be
used with the Ranger 305D. The settings are for refer-
ence.
GX 300 settings when using the K930-2 TIG Module with
an Amptrol or Arc Start Switch:
• Set the MODE Switch to the TOUCH START TIG set-
ting.
• Set the "IDLER" Switch to the "AUTO" position.
• Set the "WELDING TERMINALS" switch to the
"REMOTELY CONTROLLED" position. This will keep
the "Solid State" contactor open and provide a “cold”
electrode until the Amptrol or Arc Start Switch is
pressed.
When using the TIG Module, the OUTPUT control on
the GX 300 is used to set the maximum range of the
CURRENT CONTROL on the TIG module or an
Amptrol if connected to the TIG Module.
WIRE WELDING-CV
Connect a wire feeder to the GX 300 according to the
instructions in INSTALLATION INSTRUCTIONS
Section.
The GX 300 in the CV-WIRE mode, permits it to be
used with a variety of flux cored wire (Innershield and
Outershield) electrodes and solid wires for MIG weld-
ing (gas metal arc welding). Welding can be finely
tuned using the ARC CONTROL. Turning the ARC
CONTROL clockwise from –10 (soft) to +10 (crisp)
changes the arc from soft and washed-in to crisp and
narrow. It acts as an inductance control. The proper
setting depends on the procedure and operator prefer-
ence. Start with the dial set at 0.
The GX300 can be used with the following electrodes:
Innershield electrodes
NR-311, NS-3M, NR-207, NR-203 Ni 1%, NR-204-H.
Outershield electrodes
0S-70, 0S-71M.
Solid wires for MIG welding are: .035 (0.9 mm), and
.045 (1.1 mm), L-50 and L-56, .035 (0.9 mm) and .045
(1.1 mm) Blue Max MIG 308 LS.
For any electrodes, including the above recommenda-
tions, the procedures should be kept within the rating
of the machine.
GX 300
TYPICAL CURRENT RANGES
(1)
FOR TUNGSTEN ELECTRODES
(2)
Tungsten Electrode DCEN (-) DCEP (+) Approximate Argon Gas Flow
TIG TORCH
Diameter in. (mm)
Flow Rate C.F.H. ( l /min.)
Nozzle Size (4), (5)
1%, 2% Thoriated 1%, 2% Thoriated Aluminum
Stainless Steel
Tungsten
Tungsten
.010 (.25) 2-15
(3)
3-8
(2-4)
3-8
(2-4)
#4, #5, #6
0.020
(.50) 5-20
(3)
5-10
(3-5)
5-10
(3-5)
0.040
(1.0) 15-80
(3)
5-10
(3-5)
5-10
(3-5)
1/16
(1.6) 70-150
10-20
1 5-10
(3-5)
9-13
(4-6)
#5, #6
3/32
(2.4) 150-250
15-30
1 13-17 (6-8)
11-15
(5-7)
#6, #7, #8
1/8
(3.2)
250-400
25-40
15-23 (7-11)
11-15
(5-7)
5/32
(4.0) 400-500
40-55
21-25
(10-12)
13-17
(6-8)
#8, #10
3/16
(4.8) 500-750
55-80
23-27 (11-13)
18-22
(8-10)
1/4
(6.4)
750-1000
80-125
28-32
(13-15)
23-27
(11-13)