Lincoln Electric IM10047 RED-D-ARC GX300 - Manual (Page 21)

(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 = _ 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 CON-
TROL 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 voltage 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.
When in the TOUCH START TIG mode and when a Amptrol is
connected to the 6-Pin connector the OUTPUT dial is used to set
the maximum current range of the current control of the Amptrol.
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, retouch 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 ʻTouch Startʼ feature allows contami-
nation free starting without the use of a Hi-frequency unit. If
desired, the K930-2 TIG Module can be used with the GX-300.
The settings are for reference.
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 setting.
• Set the "IDLER" Switch to the "AUTO" position.
• Set the "WELDING TERMINALS" switch to the "REMOTELY
CONTROLLED" position. This will keep the "Solid State" con-
tactor 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 CON-
TROL 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 instruc-
tions in INSTALLATION INSTRUCTIONS Section.
The GX-300 in the CV-WIRE mode, permits it to be used with a
broad range of flux cored wire (Innershield and Outershield)
electrodes and solid wires for MIG welding (gas metal arc weld-
ing). 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 nar-
row. It acts as an inductance/pinch control. The proper setting
depends on the procedure and operator preference. Start with
the dial set at 0.
Listed below are some wires suitable for use on this machine:
• Innershield - NR-311, NS-3M, NR-207, NR-203 Ni 1%,
NR-212.
• Outershield - 0S-70, 0S-71M, 0S-71 ELITE.
• Solid wires for MIG welding - .035 (0.9 mm), and
.045 (1.1 mm), Super Arc L-50 and L-56, .035 (0.9 mm) and
.045 (1.1 mm) Blue Max MIG 308 LS.
Contact your local authorized Lincoln Electric Distributor or the
Lincoln Electric Company for specific wires used on certain
applications with this 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 5-10 (3-5) 9-13 (4-6) #5, #6
3/32 (2.4) 150-250 15-30 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)