Lincoln Electric IM520-B manual Typical Current Ranges for Tungsten Electrodes

										OPERATION
					TABLE 3					(2)
					(1)
			TYPICAL CURRENT RANGES FOR TUNGSTEN ELECTRODES
					AC				Approximate Argon
										Gas Flow Rate
		DCEN ( - )	DCEP ( + )	Unbalanced Wave		Balanced Wave				C.F.H. (1/min.)
Tungsten					1%, 2%		1%, 2%
Electrode		1%, 2%	1%, 2%		Thoriated		Thoriated						TIG Torch
Diameter		Thoriated	Thoriated	Pure	Tungsten	Pure	Tungsten				Stainless		Nozzle
in. (mm)		Tungsten	Tungsten	Tungsten	Zirconiated	Tungsten	Zirconiated		Aluminum		Steel		Size (4), (5)
.010	(.25)	2-15	(3)	2-15	2-15	2-15	---	3-8		(2-4)	3-8	(2-4)	#4, #5, #6
0.020	(.50)	5-20	(3)	5-15	5-20	10-20	5-20	5-10		(3-5)	5-10	(3-5)
0.040	(1.0)	15-80	(3)	10-60	15-80	20-30	20-60	5-10		(3-5)	5-10	(3-5)
1/16	(1.6)	70-150	10-20	50-100	70-150	30-80	60-120	5-10 (3-5)			9-13 (4-6)		#5, #6
3/32	(2.4)	150-250	15-30	100-160	140-235	60-130	100-180	13-17 (6-8)			11-15 (5-7)		#6, #7, #8
1/8	(3.2)	250-400	25-40	150-210	225-325	100-180	160-250	15-23 (7-11)			11-15 (5-7)
5/32	(4.0)	400-500	40-55	200-275	300-400	100-240	200-320	21-25 (10-12)			13-17 (6-8)		#8, #10
3/16	(4.8)	500-750	55-80	250-350	400-500	190-300	290-390	23-27 (11-13)			18-22 (8-10)
1/4	(6.4)	750-1000	80-125	325-450	500-630	250-400	340-525	28-32 (13-15)			23-27(11-13)

(1)When used with argon gas. The current ranges shown must be reduced when using argon/helium or pure helium shielding gasses.

(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.

TIG WELDING SEQUENCE OF OPERATION (2-STEP MODE)

1.Connect an Arc Start Switch or an Amptrol to the Remote Receptacle.

2.Turn on the welder, gas supply and water supply (if so equipped). The Control Panel Display and red LEDS will illuminate when the power is on.

3.Select the TIG 2-Step Weld Mode.

4.Select Local (if using an Arc Start Switch) or Remote (if using an Amptrol) current control. Set the output current using the Amps Up/Down keys. The output current setting will be displayed on the Ammeter.

5.Select Continuous High Frequency if welding with AC polarity, or Start Only High Frequency if welding with DC- polarity. High Frequency Off can be used for scratch start welding.

6.Select AC or DC- electrode polarity. See Table 2.

7.If welding with AC polarity, select Auto Balance™. This gives the optimum ratio between cleaning and penetration, automatically adjusted for the output current. If manual adjustment of the AC Wave Balance is desired, select Manual Balance, and adjust the wave balance with the Cleaning and Penetration keys. See the Advanced Features section for more information on setting and using the AC Wave Balance.

8.Select TIG Pulser On or Off. If the TIG Pulser is on, adjust the pulse frequency with the Pulses Per Second Up/Down keys. See the Advanced Features section for more information on setting and using the TIG Pulser.

9.Set the Afterflow time with the Seconds Up/Down keys. Afterflow time provides shielding gas flow (and cooling water, if used) after the weld. Use short Afterflow times with low currents and small tungstens, use long afterflow times at high output currents with large tungstens.

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