Lincoln Electric RANGER 250 LPG IM931 - Manual (Page 23)

(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 RANGER 250 LPG 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 250 LPG. The settings are for reference.
RANGER 250 LPG 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"
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
RANGER 250 LPG is used to set the maximum range of the
CURRENT CONTROL on the TIG Module or an Amptrol if con-
nected to the TIG Module.
WIRE WELDING-CV
Connect a wire feeder to the RANGER 250 LPG according to
the instructions in INSTALLATION INSTRUCTIONS Section.
The RANGER 250 LPG 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 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/pinch control. The
proper setting depends on the procedure and operator prefer-
ence. 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), 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.
RANGER 250 LPG
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)