Lincoln Electric SVM141-A Welding Operation, TIG Welding Guidelines, Twist Mate Electrode

B-6 B-6

OPERATION

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8.Digital Voltmeter - This meter displays welding voltage, as measured on the output studs of the Square Wave TIG 275. After welding is complete, the meter displays the welding voltage corre- sponding to the peak welding current and displays this value for approximately 5 seconds.

9.Thermal Protection Light - A yellow light which only lights when an over temperature situation occurs. See the Maintenance Section for more information on thermostatic protection.

10.Power Switch - Controls the input power to the Square Wave TIG 275.

11.Polarity Switch - Selects DC+, AC or DC- welding polarity without reconnecting leads. DO NOT SWITCH WHILE WELDING.

12.Twist Mate Electrode and

13.Work Connections - Easy to connect electrode and work connections. This style Electrode Connection makes the gas and current connec- tions for the TIG torch at the same time. (Adapter plugs are provided with the machine.)

14.Remote Receptacle - For Amptrol, Arc Start Switch or Robotic Interface connection.

15.Optional Water Solenoid Connections - Easy to install this optional feature which allows for water flow control for water cooled torches.

WELDING OPERATION

TIG WELDING

Familiarize yourself with the Controls and Settings Section before attempting operation of the Square Wave TIG 275.

TIG WELDING GUIDELINES

TIG welding can be done in either the TIG 2-Step or the TIG 4-Step Weld Mode. TIG 2-Step is typically used with Hand or Foot Amptrols, with Remote Current control. TIG 4-Step typically uses an Arc Start switch and Local Current Control, because it provides a very brief current upslope, and a .5 to 10 second adjustable current downslope. TIG 4-Step also functions like a trigger interlock, making it unnecessary to hold down the Arc Start switch during a weld. This feature requires that the remote control device in use must have separate Arc Start and Output Control mecha- nisms. Read the TIG Welding Sequence of Operation sections for more details on 2-Step and 4-Step opera- tion.

Recommended tungsten electrode sizes, stickouts, currents, cup or nozzle sizes are shown in Table B.1.

SINCE WELDING APPLICATIONS CAN VARY, THIS CHART IS INTENDED AS A GUIDE ONLY.

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												(2)
		TABLE B.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						(4)	TIG torch nozzle “sizes” are in multiples of 1/16ths of an inch:
pure helium shielding gasses.							#4 = 1/4 in.	(6 mm)
(2) Tungsten electrodes are classified as follows by the American Welding Society (AWS):							#5 = 5/16 in.	(8 mm)
Pure . . . . . . . . . . . . . . . EWP							#6 = 3/8 in.	(10 mm)
1% Thoriated . . . . . . . . EWTh-1							#7 = 7/16 in.	(11 mm)
2% Thoriated . . . . . . . . EWTh-2							#8 = 1/2 in.	(12.5 mm)
Though not yet recognized by the AWS, Ceriated Tungsten is now widely accepted as a substitute for							#10 = 5/8 in.	(16 mm)
2% Thoriated Tungsten in AC and DC applications.					(5)		TIG torch nozzles are typically made from alumina ceramic. Special applications may require lava nozzles,
(3) DCEP is not commonly used in these sizes.							which are less prone to breakage, but cannot withstand high temperatures and high duty cycles.

SQUARE WAVE TIG 275